The culturable bacterial community of frass produced by larvae of Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) in the Canary island date palm

Aims:  Larvae of the red palm weevil (RPW) Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) feed inside palm stem tissues, making galleries and producing a wet fermenting frass. We characterized the culturable bacteria associated with frass produced by tunnelling larvae inside the Canary island date palms and investigated the role of frass and gut bacteria in plant polymers breakdown. Methods and Results:  A culture-dependent method was used to isolate bacteria from frass and noninfested palm tissues. Bacterial isolates were grouped into operational taxonomic units based on polymorphisms in the ITS-PCR profiles, and representative isolates were identified by partial sequencing …

The bioremediation potential of the Priolo Harbour (SR, Italy): isolation, identification and catabolic ability of hydrocarbonoclastic bacteria

The petrochemical site of Priolo-Augusta-Melilli (Sicily, Italy), is a Site of National Interest (SIN) due to high levels of contamination of the coastline and its remediation is urgently needed. Successful remediation strategies relying on the catabolic potential of marine hydrocarbonoclastic bacteria (HCB) have been described. HCB are specialised hydrocarbon (HC)-degrading marine bacteria that use HC almost exclusively as unique carbon and energy source and become dominant in oil-impacted environments. In order to identify the key hydrocarbon degraders and explore the natural bioremediation potential of the contaminated area, sediment cores and sea water were collected inside the Priolo H…

Gene cloning and characterization of an alkane hydroxylase system in the long chain n-alkane- degrader Gordonia sp. SoCg

ANALISI DELLA COMUNITÀ MICROBICA INTESTINALE DI Reculitermes lucifugus (ROSSI) (ISOPTERA: RHINOTERMITIDAE)

Reticulitermes lucifugus è una specie di termite diffusa in Italia e che causa gravi danni alle strutture legnose di monumenti storici e artistici. L’intestino delle termiti ospita una comunità microbica di batteri e flagellati, responsabile della degradazione del materiale lignocellulosico. Studi preliminari sulla comunità microbica dei simbionti di R. lucifugus, hanno descritto alcune specie di protozoi, ma non ci sono ancora informazioni sui simbionti batterici. Al fine di caratterizzare la comunità microbica intestinale di R. lucifugus è stato utilizzato un approccio molecolare coltura indipendente e colture di arricchimento per l’isolamento dei batteri cellulosolitici. Per l’analisi co…

Degradazione di pesticidi organofosforici in matrici ambientali

Matrici quali acqua, suolo ed aria sono costantemente soggette a forti pressioni antropiche. I pesticidi pur avendo apportato grandi benefici alle attività agricole influiscono negativamente sugli equilibri degli ecosistemi. Circa 85-90% dei principi attivi applicati in agricoltura non raggiunge gli organismi a cui sono destinati, ma viene disperso nell’ambiente. In tale contesto l’individuazione di microrganismi deputati alla loro degradazione diventa un importante mezzo per la salvaguardia ambientale e della salute umana. Lo scopo del presente lavoro è stato quello di isolare batteri del suolo capaci di degradare composti organofosforici, i quali rivestono una notevole importanza nelle pr…

Soil Quality Characterization of Mediterranean Areas under Desertification Risk for the Implementation of Management Schemes Aimed at Land Degradation Neutrality

Soil is a key component of ecosystems as it provides fundamental ecosystem functions and services, first of all supporting primary productivity, by physical, chemical and biological interaction with plants. However, soil loss and degradation are at present two of the most critical environmental issues. This phenomenon is particularly critical in Mediterranean areas, where inappropriate land management, in combination with the increasingly harshening of climatic conditions due to Climate Change, is leading to significant land degradation and desertification and is expected to worsen in the future, leading to economic and social crisis. In such areas, it is of fundamental importance to apply …

Settlement performance of the Mediterranean reef-builders Dendropoma cristatum (Biondi 1859) in response to natural bacterial films.

The gastropod Dendropoma cristatum is a biogenic engineer of the central Mediterranean, forming reefs along the lower rocky intertidal fringe with a remarkable ecological role. To understand whether reef-associated biofilm cultivable bacterial and biofilm ageing may trigger the settlement of the juvenile snails, a combination of laboratory techniques and field experiments was used. Reef-associated biofilm cultivable bacteria were isolated, and a settlement-choice experiment was performed in situ on artificial biofilms composed of i) a mixture of six biofilm-forming selected isolates, ii) all the cultivable bacteria, and iii) 13-, 23-, 32-day old biofilms formed under natural conditions. Ove…

Microbes and Persistent Organic Pollutants in the Marine Environment

Marine pollution has increased reaching the entire marine environment, from the surface to the deepest sediment, and has become more concerning in the last 70 years. Persistent organic pollutants (POPs) are a fraction of ocean waste that includes, among the others, polycyclic aromatic hydrocarbons (PAHs) and plastic polymers. These chemicals have an extremely long half-life, and (bio)accumulate and damage the marine flora and fauna, and, ultimately, human health. Some organisms have evolved enzymes to attack POPs in the environment and transform them into biomass and CO2. Several microorganisms degrade many POPs in relatively short time. A wide variety of bacteria has been isolated with dif…

Innovative ready to use carrier-bacteria devices for bioremediation of oil contaminated water

Bioremediation, that uses microorganisms to remove environmental pollutants, is the best way of restoring the environment due to its low cost and sustainability. Immobilization of microorganisms capable of degrading specific contaminants significantly promotes bioremediation processes. An innovative ready to use bioremediation system to clean up oil-contaminated water was developed immobilizing highly performant marine and soil HC degrading bacteria, on biodegradable oil-absorbing carriers. Two soil Actinobacteria (Gordonia sp. SoCg, Nocardia sp. SoB) and two marine Gammaproteobacteria (Alcanivorax sp. SK2, Oleibacter sp.5), were immobilized on biopolymeric membranes prepared by electrospin…

BIODIVERSITA’ DELLE COMUNITA’ BATTERICHE IN UN SUOLO SOTTOPOSTO A BIORISANAMENTO IN MICROCOSMO

Gli idrocarburi (HC) sono uno dei principali inquinanti ambientali. Una tecnologia promettente per il trattamento di siti contaminati si basa sulla biodegradazione degli inquinanti da parte di popolazioni microbiche capaci di utilizzare HC come fonte di carbonio ed energia (Biorisanamento). La necessità di risanare siti contaminati richiede da una parte la caratterizzazione delle comunità microbiche coinvolte nella biodegradazione, dall’altra lo sviluppo di interventi volti a migliorare il potenziale metabolico dei microrganismi degradatori. La nostra attività di ricerca ha avuto come obiettivo quello di caratterizzare e analizzare la biodiversità di comunità microbiche di un suolo contamin…

MAP OF 3D DISTRIBUTION OF HYDROCARBONOCLASTIC BACTERIA IN MEDITERRANEAN SEA

The obligate hydrocarbonoclastic bacteria (OHCB) have been recognized and shown to play a significant role in the biological removal of hydrocarbons from polluted marine waters. The introduction of oil or hydrocarbons into seawater leads to successive blooms of a relatively limited number of indigenous marine bacterial genera (Alcanivorax, Marinobacter, Thallassolituus, Cycloclasticus and Oleispira) which are present at low or undetectable levels before the polluting event. The types of OHCB that bloom depend directly from level and type of pollution and from parameters as the latitude/temperature, salinity, redox etc.... In this work, using data present in GeneBank we have create a virtual…

Soils as natural filters for GHG: an imbalance between the expected CH4 fluxes and the direct measurements

The final composition of the atmosphere results from several processes and exchanges between all the Earth’s spheres. Some of these are widely known and others, such as the methane degassing from hydrothermal areas, are still understudied. Methane plays a key role in climate change being an efficient greenhouse gas. Although it would be crucial, the total CH4 output from geogenic sources is still not well defined; limitations in CH4 output estimations are due to many factors concerning a scarce dataset availability, difficulty in direct measurements, and interaction with methane-consuming microbiota in the soil. Often, the CH4 flux estimation was obtained indirectly, e.g. cross-correlating …

Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy)

Abstract. Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission was previously estimated in about 2.5 t a−1. Laboratory incubation experiments with three top-soil samples from Favara Gra…

The Root Mycobiota of Betula aetnensis Raf., an Endemic Tree Species Colonizing the Lavas of Mt. Etna (Italy)

Betula aetnensis is an endemic tree of high conservation value, which thrives on the nutrient-poor volcanic soils of Mount Etna. Since plant–microbe interactions could play a crucial role in plant growth, resource uptake, and resistance to abiotic stresses, we aimed to characterize the root and rhizosphere microbial communities. Individuals from natural habitat (NAT) and forest nursery (NURS) were surveyed through microscopy observations and molecular tools: bacterial and fungal automated ribosomal intergenic spacer analysis (ARISA), fungal denaturing gradient gel electrophoresis (DGGE). B. aetnensis was found to be simultaneously colonized by arbuscular (AM), ectomycorrhizal (ECM), ericoid…

A modified culture medium for improved isolation of marine vibrios

Abstract Marine Vibrio members are of great interest for both ecological and biotechnological research, which often relies on their isolation. Whereas many efforts have been made for the detection of food‐borne pathogenic species, much less is known about the performances of standard culture media toward environmental vibrios. We show that the isolation/enumeration of marine vibrios using thiosulfate‐citrate‐bile salts‐sucrose agar (TCBS) as selective medium may be hampered by the variable adaptability of different taxa to the medium, which may result even in isolation failure and/or in substantial total count underestimation. We propose a modified TCBS as isolation medium, adjusted for mar…

The importance of methanotrophic activity in geothermal soils of Pantelleria island (Italy)

Methane is a major contributor to the greenhouse effect, its atmospheric concentration being more than doubled since the XIX century. Every year 22 Tg of methane are released to the atmosphere from several natural and anthropogenic sources. Natural sources include geothermal/volcanic areas but the estimation of the total methane emission from these areas is currently not well defined since the balance between emission through degassing and microbial oxidation within the soils is not well known. Microbial oxidation in soils contributes globally for about 3-9% to the removal of methane from the atmosphere and recent studies evidenced methanotrophic activity also in soils of volcanic/geotherma…

PARTIAL SEQUENCING OF THE BETA-GLUCOSIDASE-ENCODING GENE FROM YEAST STRAINS ISOLATED FROM MUSTS AND WINES

The aim of the present work was the identification of the gene encoding for β-glucosidase and its partial sequencing in the strainsPichia anomala AL112,Hanseniaspora uvarum Y8 andSaccharomyces cerevisiae AL41. To this aim degenerated primers, designed on the basis of aminoacid similarities of four known yeast β-glucosidases, have been used in PCR amplifications. An expected fragment of about 200 bp was amplified from all the DNAs, cloned and sequenced. Sequence homology demonstrated for the first time the presence of a β-glucosidase encoding gene inHanseniaspora uvarum andSaccharomyces cerevisiae.

Isolation, identification and metabolic characterization of hydrocarbonoclastic bacteria from a polluted harbour in Sicily (Italy)

The petrochemical site of Priolo-Augusta-Melilli (Sicily, Italy), is a Site of National Interest (SIN) due to high levels of environmental contamination of the coastline and a specific "national program of environmental remediation and restoration" was developed in order to allow remediation and restoration of contaminated sites. In order to identify the key hydrocarbon degraders and explore the natural bioremediation potential of the contaminated area, a total of six sediment and sea water cores were collected inside the Priolo Harbour (SR, Italy). After biological (bacterial counts, PCR-DGGE) and chemical-physical characterization (quali-, quantitative measures of hydrocarbons and heavy m…

Temporal dynamic of biofilms enhances the settlement of the central-1 Mediterranean reef2 builder Dendropoma cristatum (Biondi, 1859)

Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum . In order to elucidate which biofilm features support a higher settlement of this species, we analyse the structure and composition of a marine biofilm over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm extent on the substrat…

Biodegradation Potential of Oil-degrading Bacteria Related to the Genus Thalassospira Isolated from Polluted Coastal Area in Mediterranean Sea

Three bacterial species related to the genus Thalassospira (T. lucentensis, T. xianhensis and T. profundimaris), isolated from polluted sediment and seawater samples collected from Priolo Bay (eastern coast of Sicily, Ionian Sea), were analyzed for their biotechnological potential. For this purpose, the presence of specific catabolic genes associated to aliphatic and aromatic hydrocarbon metabolism, the production of biosurfactants and emulsification activity, the capability to degrade oil-derived linear, branched, cyclic alkanes, and polycyclic aromatic hydrocarbons (PAHs) were evaluated. Alkane hydroxylase gene (alkano-monoxygenase alkb and citocrome P450) were present in genome of all st…

The early plastisphere of biodegradable and non-biodegradable plastic films in marine environment

Introduction Plastic items are the most common form of marine debris and plastic accumulation in marine ecosystems is a serious environmental issue. One possible solution to reduce the amount of synthetic polymers released in the environment is to substitute them with bio-based polymers. When released in marine environments, plastics are readily colonized by biofilm-forming microorganisms, the so called “plastisphere community”, which may include pathogenic, invasive and plastic-degrading species; the composition and influence of the plastisphere on the fate of plastic is largely unknown. The aim of this study is to investigate the early biofilm formation and the structure and diversity of …

Isolamento e Caratterizzazione di rizobi isolati da leguminose legnose per il recupero di ecosistemi degradati.

Bioremediation of chronically oil-polluted marine sediment using beats of hydrocarbons-degrading bacteria

Bioremediation is a good kind of "green biotechnology" based on the microorganisms ability to degrade hydrocarbons fractions. In this work sediment samples were collected from the industrial harbor of Priolo Gargallo (Augusta, Syracuse, Sicily - Italy), a chronically polluted area. Enrichment cultures and microbial isolation were performed. Amoung 258 bacteria and 5 consortia isolated, strain S1 (Alcanivorax borkumensis, 98%) and two consortia (PSO and PSM) showed degradation rates of ~98% for linear and polycyclic aromatic hydrocarbons (PHAs) after 10 days of incubation (25±1°C, shaking 100 g). Taxonomic analysis (16S clone libraries) of consortia showed as dominant genera hydrocarbonoclas…

Bacterial diversity in soils vulnerable to desertification

Introduction Mediterranean soils are experiencing increasingly negative effects of climate change due to drought and extreme weather phenomena that negatively affect agriculture, already suffering social and economic constraints. The soil microbiota is recognized as key player in both diversity and productivity of terrestrial ecosystems and it is mandatory to include its role in sustainable agronomic management. The LIFE Project DESERT-ADAPT - Preparing desertification areas for increased climate change - (http://www.desert-adapt.it/) focuses on agricultural adaptation measures aimed at reverting ongoing desertification trends (while improving the socioeconomic conditions of farmers). In or…

CHANGE IN VOLUME AND MORPHOLOGY IN CULTURES OF OLEISPIRA ANTARCTICA AS A FUNCTION OF TEMPERATURE AND SUBSTRATES USED

Bacterial population under nutritional and physic stress react in order to adequate cell metabolism and physiology to stressful conditions. One of the most frequently observed behaviours in the stress-starvation response of gram-negative bacteria is the size reduction and cell morphology conversion from rod to resistant shape-form. In such framework, we report here on morphology (cell volume and cell shape) variations in psychrophilic strain Oleispira antarctica RB 8T under different growth temperature and different hydrocarbons mixtures sources. Six different hydrocarbons mixtures (car commercial diesel, commercial crude oil engine; 2 different bilge waters, military jet fuel and crude oil…

Profiling microbial communities in hyperalkaline waters of the Kizildag ophiolite complex (Turkey).

It has recently been hypothesized that life on Earth could have been originated in hyperalkaline waters related to serpentinization of ophiolitic rocks, despite their extreme conditions (high pH and very low levels of nutrients). Five hyperalkaline springs of the Kizildag ophiolite complex (Turkey) were characterized. The dominant gases are either H2, CH4 or N2 . Bacterial diversity, analysed by RISA (Ribosomal Intergenic Spacer Analysis) revealed different profles for each spring. Sequencing of excised DNA bands allowed to identify the presence of Bacillus, Ralstonia, Pseudoalteromonas., Ureibacillus, Alicycliphilus, Anaerococcus. 16S ribosomal DNA sequencing by Illumina is in progress. Th…

Methylacidimicrobium thermophilum AP8, a Novel Methane- and Hydrogen-Oxidizing Bacterium Isolated From Volcanic Soil on Pantelleria Island, Italy

The Favara Grande is a geothermal area located on Pantelleria Island, Italy. The area is characterized high temperatures in the top layer of the soil (60°C), low pH (3–5) and hydrothermal gas emissions mainly composed of carbon dioxide (CO2), methane (CH4), and hydrogen (H2). These geothermal features may provide a suitable niche for the growth of chemolithotrophic thermoacidophiles, including the lanthanide-dependent methanotrophs of the phylum Verrucomicrobia. In this study, we started enrichment cultures inoculated with soil of the Favara Grande at 50 and 60°C with CH4 as energy source and medium containing sufficient lanthanides at pH 3 and 5. From these cultures, a verrucomicrobial met…

Biodegradazione di miscele di gasolio in suoli contaminati

Il biorisanamento mediante l’utilizzo di microrganismi ha un ruolo fondamentale nelle pratiche di trasformazione di molecole potenzialmente tossiche quali gli idrocarburi, che quotidianamente vengono riversati negli ecosistemi provocando fenomeni di antropizzazione in equilibri naturali particolarmente sensibili. Numerosi ceppi batterici sono abili degradatori e mineralizzatori di sostanze inquinanti xenobiotiche di sintesi e recalcitranti non esistenti in natura, quali i derivati di idrocarburi aromatici e policlorobifenili (PCB). Mediante colture su mezzo minerale Bushnell-Haas agarizzato (BH) in presenza di una miscela di idrocarburi come unica fonte di carbonio sono stati isolati 5 cepp…

biotecnologiche di batteri del suolo

Comparison of different primer sets for use in Automated Ribosomal Intergenic Spacer Analysis of complex bacterial communities.

ABSTRACT ITSF and ITSReub, constituting a new primer set designed for the amplification of the 16S-23S rRNA intergenic transcribed spacers, have been compared with primer sets consisting of 1406F and 23Sr (M. M. Fisher and E. W. Triplett, Appl. Environ. Microbiol. 65:4630-4636, 1999) and S-D-Bact-1522-b-S-20 and L-D-Bact-132-a-A-18 (L. Ranjard et al., Appl. Environ. Microbiol. 67:4479-4487, 2001), previously proposed for automated ribosomal intergenic spacer analysis (ARISA) of complex bacterial communities. An agricultural soil and a polluted soil, maize silage, goat milk, a small marble sample from the façade of the Certosa of Pavia (Pavia, Italy), and brine from a deep hypersaline anoxi…

Soil microbial diversity has an impact on plant diversity and safeguard

Diversity of microbial plant symbionts has an impact on plant diversity. Examples are given for Mediterranean species.

High diversity of root endophytes in the pioneer endemic Betula aetnensis Raf. colonizing volcanic lavas

Introduction Betula aetnensis Raf. is an endemic tree species native to Sicily of particular conservation value, that establishes on nutrient-poor and water-limited lava of Etna volcano. In these harsh conditions plant-microbe interactions could play a crucial role in plant growth, resource uptake and resistance to abiotic stresses. The aim of this study is to investigate the root-associated microbial community of B. aetnensis growing in its natural habitat. The comparison between individuals from natural habitats and nursery-grown seedlings aims to assess the symbiotic status of plant material used for afforestation purposes. Materials and Methods Betula aetnensis individuals were collecte…

Applicazioni biotecnologiche di batteri del suolo

BIODEGRADING BIOFILMS ON INNOVATIVE BIOPOLYMERIC SUPPORTS

ABSTRACT Water bioremediation is traditionally carried out using ‘ free ’ bacterial cells, however, in recent years, utilization of ‘immobilized’ bacterial cells on adsorbing matrices, has gained attention as a promising technique due to biotechnological and economic benefits (Sonawane et al., 2022). Bacterial biofilms show greater resilience, survival and degradative activity for longer periods than cells in the planktonic state (Alessandrello et al., 2017); moreover immobilization reduces bioremediation costs, eliminate cell dilution and dispersion in the environment (Bayat et al., 2015). Possible applications of immobilized biodegrading bacteria require long-term survival and maintenance…

Polycaprolactone-based scaffold for oil-selective sorption and improvement of bacteria activity for bioremediation of polluted water

Abstract A novel floatable and biodegradable sponge for the selective absorption of oil from water and potentially useful as cell carrier for bioremediation treatments was prepared in polycaprolactone (PCL). The eco-friendly process for fabricating the PCL sponge does not involve either synthetic routes or organic solvents, thus minimizing environmental hazard. In particular, the 3D porous materials have been prepared by mixing in the melt the polymer matrix with two water-soluble porogen agents (NaCl and PEG) and thereafter leaching the obtained PCL/NaCl/PEG composites in water. The PCL sponges here proposed are capable to remove different types of oily pollutants (up to 500 wt%), and were…

The transformation of agricultural systems into agro-forestry systems as a system of adaptation to climate and economic changes: some Sicilian case studies

Many traditional agricultural systems show different limits both in ecological and economic terms. These limits are exacerbated by the increasingly extreme climatic conditions which in the southern regions are manifested essentially in a concentration of rainfall and in increasingly intense dry periods. As part of the LIFE (Desert Adapt) project, some companies involved in the project are modifying their cultivation systems without changing the land use destination. This appears possible by introducing elements of diversification which make the system more resilient as a whole but which guarantees safer economic resources. In particular, in the case of a "classic" agricultural company Calta…

A large catabolic plasmid carries the genes for the dehalogenation of 4-chlorobenzoate in arthrobacter ramosus FG1

Exploring long chain n-alkane metabolism in Gordonia sp. strain SoCg

Many microorganisms are able to degrade aliphatic hydrocarbons and a relationship between n-alkane utilization and storage compound synthesis has been described in bacteria. The Gram positive GC-rich n-alkane degrader Gordonia sp. strain SoCg, isolated from a long-term accidentally contaminated beach in Sicily, is able to grow on long n-alkanes up to. It carries a single copy of the alkane hydroxylase gene alkB on its chromosome and its alk cluster revealed a genomic organization similar to other alk clusters of alkane-degrading Gram positive bacteria. The alk gene expression, analysed by Real-time RT-PCR, is induced by n-hexadecane and n-triacontane and coupled to alkane consumption. Inter…

Analisi della comunità microbica intestinale di Reticulitermes lucifugus (Rossi) (Isoptera: Rhinotermitidae).

L’intestino delle termiti ospita una comunità microbica di batteri e flagellati anaerobi, responsabile della degradazione del materiale lignocellulosico. La digestione della lignocellulosa da parte delle termiti dipende dalla simbiosi con microrganismi procarioti ed eucarioti che vivono nel loro intestino. I microrganismi trasformano la cellulosa in zuccheri e acetato, producendo idrogeno, metano e anidride carbonica. Abbiamo analizzato la comunità microbica intestinale di Reticulitermes lucifugus lucifugus, una delle due specie di termiti italiane, che vive in ambienti sotterranei, è distruttiva per le strutture legnose degli ambienti urbani causando seri danni ai monumenti storici e può c…

GENE CLONING AND CHRACTERIZATION OF AN ALKANE HYDROXYLASE SYSTEM IN A LONG CHAIN N.ALKANE. DEGRADER GORDONIA SP.

Isolation, characterization and determination of biotechnological potential of oil-degrading bacteria from Algerian centre coast

Aims The Algerian coastline is exposed to several types of pollution, including hydrocarbons. The aim of this work was to isolate oil-degrading bacteria and to explore the intrinsic bioremediation potential of part of its contaminated harbour. Methods and results A collection of 119 strains, capable to grow on mineral medium supplemented with hydrocarbons, were obtained from polluted sediment and seawater collected from Sidi Fredj harbour (Algiers). Twenty-three strains were selected for further studies. Sequencing of the 16S rRNA gene showed that most isolates belong to genera of hydrocarbonoclastic bacteria (Alcanivorax), generalist hydrocarbons degraders (Marinobacter, Pseudomonas, Gordo…

Blue biotechnology: oil bioremediation using hydrocarbon-degrading bacteria immobilized on biodegradable membranes

A novel bioremediation system to clean up oil contaminated water was developed combining hydrocarbon (HC) degrading bacteria immobilized and polylactic acid (PLA) or polycaprolactone (PCL) membranes prepared by electrospinning. The bioremediation efficiency was tested on crude oil using highly performant HC degrading bacterial strains isolated from marine and soil environments. The membrane morphology, the microbial adhesion and proliferation were evaluated using scanning electron microscopy (SEM). The SEM analysis highlighted that the fibers of the electrospun mats were in nanoscale with a similar diameter size distribution. The electrospun membranes exhibited high oil absorption capacity …

Diversity of rhizobia nodulating wild shrubs of Sicily and some neighbouring islands

Abstract Legume shrubs have great potential for rehabilitation of semi-arid degraded soils in Mediterranean ecosystems as they establish mutualistic symbiosis with Nfxing rhizobia. Eighty-eight symbiotic rhizobia were isolated from seven wild legume shrubs native of Sicily (Southern Italy) and grouped in operational taxonomic units (OTU) by analysis of the ribosomal internal transcribed spacer (ITS) polymorphism. Partial sequencing of 16S rRNA gene of representative isolates of each OTU revealed that most Genisteae symbionts are related to Bradyrhizobium canariense, B. japonicum and B. elkanii. Teline monspessulana was the only Genistea nodulated by Mesorhizobium strains, and Anagyris foeti…

Including the soil microbiota in the quality evaluation of soils vulnerable to desertification

The soil microbiota is recognized as key player in both diversity and productivity of terrestrial ecosystems and it is mandatory to include its role in soil quality evaluation. Drivers of below-ground diversity are still largely unknown and is still unclear if the main soil features (i.e. soil organic matter, nutrient and water availability) are potential drivers of microbial diversity or are regulated by it. Increasingly negative effects of climate change due to drought and extreme weather phenomena are causing Mediterranean soil degradation that rapidly degenerates to desertification. Within the LIFE Desert-Adapt project we investigated bacterial diversity in soils of southern Europe unde…

Isolation of Gram positive n-alkane degraders from a hydrocarbon contaminated sicilian shoreline

High diversity of methanotrophic bacteria in a geothermal site: Pantelleria island

The gut microbiota of larvae of Rhynchophorus ferrugineus Oliver (Coleoptera: Curculionidae)

Background: The red palm weevil (RPW) Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) is one of the major pests of palms. The larvae bore into the palm trunk and feed on the palm tender tissues and sap, leading the host tree to death. The gut microbiota of insects plays a remarkable role in the host life and understanding the relationship dynamics between insects and their microbiota may improve the biological control of insect pests. The purpose of this study was to analyse the diversity of the gut microbiota of field-caught RPW larvae sampled in Sicily (Italy). Results: The 16S rRNA gene-based Temporal Thermal Gradient Gel Electrophoresis (TTGE) of the gut microbiota of RPW …

Blue biotechnology: enhancement of bioremediation using bacterial biofilms on biodegradable scaffolds

Petroleum hydrocarbons are still the most threatening environmental pollutants. A promising non invasive and low-cost technology for the treatment of contaminated sites is based on bioremediation by biodegrading microorganism endowed with catabolic ability towards oil and derivatives. New methods are needed to enhance and optimize natural biodegradation, such as the immobilization of hydrocarbons degraders in many types of supports. We developed a scaffold-bacteria bioremediation system to clean up oil contamination based on degradable 3D scaffolds. The polycaprolactone component is biodegradable, produced in the melt, i.e. at low cost and without the use of toxic solvents. The biofilm is m…

Invasional meltdown via horizontal gene transfer of a European symbiosis island variant in North American nodule symbionts of Cytisus scoparius

New data from sites in Spain, Sicily and North America establish that the spread of the European legume Cytisus scoparius (Scotch broom) across North America involved the concurrent invasion of a European mobile genetic element (symbiosis island [SI]) into North American Bradyrhizobium nodule bacteria. At four SI loci, bacteria from nine C. scoparius populations across the continent were all identical to haplotypes present in European Bradyrhizobium strains. At seven non-symbiotic (housekeeping) loci, these American C. scoparius bacteria grouped into eight diverse lineages related to, or in some cases identical to, symbionts from several native North American legumes. Inoculation experiment…

Procedimento per la biodegradazione di oli e/o grassi esausti

Biodegradazione di n-alcani a catena lunga in ecosistemi contaminati

Biological diversity of the microbial film associated to the central-Mediterranean Dendropoma cristatum (Biondi, 1859) reefs.

Microbial films may provide physical and bio-chemical cues which positively affect the settlement dynamic of a variety of benthic marine organisms, driving the development of ecosystems. Also for the Mediterranean intertidal reef-builder Dendropoma cristatum (Biondi, 1859), biofilm maturity has been found to enhance the settlement pattern. However, the microbial diversity associated with these bioconstructions has never been described. This study investigates the D. cristatum reef bacterial assemblage composition and temporal evolution in two localities in the northwest of Sicily. Biological diversity of the reef-associated biofilm and of 3 progressively older biofims obtained on artificial…

The gut bacterial community of the red palm weevil Rhynchophorus ferrugineus (Olivier, Coleoptera, Curculionidae) larvae

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier, Coleoptera, Curculionidae) is the major pest of palm trees in the Mediterranean area. Damages are caused mainly by the endophytophagous larvae that consume the palm tender soft tissues making galleries and producing a wet “frass” with a characteristic fermented odour. The culturable bacterial community associated to the frass produced by RPW larvae inside Phoenix canariensis trees is mainly composed of facultative anaerobe gamma-proteobacteria that have their closest phylogenetic relatives in the gut microbiome of other endophytophagous and xilophagous coleopteran as bark beetles and other plant biomass-degrading insects (leaf-c…

Microbial communities of polluted sub-surface marine sediments

Abstract Microbial communities of coastal marine sediment play a key role in degradation of petroleum contaminants. Here the bacterial and archaeal communities of sub-surface sediments (5–10 cm) of the chronically polluted Priolo Bay (eastern coast of Sicily, Italy), contaminated mainly by n-alkanes and biodegraded/weathered oils, were characterized by cultural and molecular approaches. 16S-PCR-DGGE analysis at six stations, revealed that bacterial communities are highly divergent and display lower phylogenetic diversity than the surface sediment; sub-surface communities respond to oil supplementation in microcosms with a significant reduction in biodiversity and a shift in composition; the…

Degradation of long-chain n-alkanes in soil microcosms by two actinobacteria

The ability of two recently isolated actinobacteria, that degrade medium and long chain n-alkanes in laboratory water medium, was investigated in soil microcosms using different standard soils that were artificially contaminated with n-alkanes of different length (C(12)- C(20)- C(24)- C(30)). The two strains, identified as Nocardia sp. SoB and Gordonia sp. SoCp, revealed a similar high HC degradation efficiency with an average of 75% alkane degraded after 28 days incubation. A selectivity of bacteria towards n-alkanes of different length was detected as well as a consistent effect of soil texture and other soil physical chemical characteristics on degradation. It was demonstrated the specif…

Isolation of Gram-positive n-alkane degraders from a hydrocarbon-contaminated Mediterranean shoreline.

Aims: To investigate the petroleum hydrocarbon (HC)-degrading potential of indigenous micro-organisms in a sandy Mediterranean coast, accidentally contaminated with petroleum-derived HCs. Methods and Results: Using culturable methods, a population of Gram-positive n-alkane degraders was detected in the contaminated soil. Five isolates, identified as one Nocardia, two Rhodococcus and two Gordonia strains, were able to degrade medium- and long-chain n-alkanes up to C36 as assessed by growth assays and gas chromatography-mass spectrometry analysis. Diverging alkane hydroxylase-encoding genes (alkB) were detected by PCR, using degenerated primers, in all the strains; multiple sequences were obt…

Una collezione di rizobi da leguminose mediterranee per il recupero ambientale

The culturable bacterial community of frass produced by larvae of Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) in the Canary island date palm.

Aims: Larvae of the red palm weevil (RPW) Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) feed inside palm stem tissues, making galleries and producing a wet fermenting frass. We characterized the culturable micro-organisms associated with frass produced by tunnelling larvae inside the Canary island date palms and investigated the role of frass and gut bacteria in plant polymers breakdown. Methods and Results: A culture-dependent method was used to isolate bacteria from frass and noninfested palm tissues. Bacterial isolates were grouped into operational taxonomic units based on polymorphisms in the ITS-PCR profiles, and representative isolates were identified by partial sequenci…

Hydrogen and Carbon Monoxide-Utilizing Kyrpidia spormannii Species From Pantelleria Island, Italy

Volcanic and geothermal areas are hot and often acidic environments that emit geothermal gasses, including H2, CO and CO2. Geothermal gasses mix with air, creating conditions where thermoacidophilic aerobic H2- and CO-oxidizing microorganisms could thrive. Here, we describe the isolation of two Kyrpidia spormannii strains, which can grow autotrophically by oxidizing H2 and CO with oxygen. These strains, FAVT5 and COOX1, were isolated from the geothermal soils of the Favara Grande on Pantelleria Island, Italy. Extended physiology studies were performed with K. spormannii FAVT5, and showed that this strain grows optimally at 55°C and pH 5.0. The highest growth rate is obtained using H2 as ene…

Effects of Arbuscular Mycorrhizal Fungi on the Vegetative Vigor of Ailanthus altissima (Mill.) Swingle Seedlings under Sustained Pot Limitation

In order to invade new ecosystems, invasive alien plants need to cope with different microbial communities. Whilst the ability to avoid antagonists is well recognized, the opportunity to establish mutualistic associations is less known, even in widespread invasive species such as Ailanthus altissima (Mill.) Swingle. We sought to evaluate whether the beneficial effects of arbuscular mycorrhizal fungi (AMF) on Ailanthus seedlings are maintained over time, under prolonged pot limitation. We compared three-month-, three-year- and four-year-old mycorrhizal seedlings grown in natural forest soil (NT) with seedlings grown in sterilized (ST) and non-mycorrhizal (NM) soils, in pots of 3.4 L (22 &tim…

Diversità microbica dei sedimenti marini dell’Area Marina Protetta di Capo Gallo-Isola delle Femmine (Palermo) in relazione alla pressione antropica.

I batteri costituiscono una frazione significativa della biomassa totale in mare e la loro presenza risulta ancora più accentuata nei sedimenti. Le comunità microbiche marine giocano un ruolo chiave nei processi degradativi della sostanza organica sedimentaria e nella sua reintroduzione nelle reti trofiche. Tuttavia la piccola percentuale di batteri marini coltivabili (3-7%) pone un severo limite alla conoscenza della biodiversità microbica. Allo scopo di contribuire a definire i livelli di impatto antropico compatibili con la funzione di ciascuna zona dell’Area Marina Protetta è stata caratterizzata la comunità batterica totale indigena dei sedimenti. Lo studio è stato effettuato utilizzan…

Oil-degrading bacteria from a membrane bioreactor (MBR) system for treatment of saline oily waste: isolation, identification and characterization of the biotechnological potential

This study was focused on the microbial community characterization during operation of a Membrane Bioreactor System, used for the treatment of saline oily wastes, originated from marine transportation. A collection of forty-two (42) strains was obtained during microbiological screening and the bacterial diversity analyzed by amplification and 16S rRNA sequencing. Taxonomic analysis has shown a high level of identity with recognized sequences for a total of seven (7) distinct bacterial genera (Alcanivorax, Erythrobacter, Marinobacter, Microbacterium, Muricauda, Rhodococcus and Rheinheimera). The biotechnological potential of all isolates was identified by the estimate of two key factors, suc…

Differential proteomic analysis of an engineered Streptomyces coelicolor strain reveals metabolic pathways supporting growth on n-hexadecane

The alkB gene, encoding an alkane monooxygenase in the actinomycete Gordonia sp. SoCg, was expressed in the non-alkane-degrading actinomycete Streptomyces coelicolor M145. The resulting engineered strain, M145-AH, can grow on n-hexadecane as sole carbon source. To unravel proteins associated with growth on n-alkanes, proteome of M145-AH after 6, 24, and 48 h of incubation in the Bushnell-Haas (BH) mineral medium containing n-hexadecane as sole carbon source (H condition) and in BH without any carbon source (0 condition) were compared using 2D-differential gel electrophoresis. Proteome analysis revealed significant changes only at 48 h, showing 48 differentially abundant proteins identified …

Isolation and characterization of hydrocarbonoclastic bacteria from Algerian coast

Backgrounds The contamination of marine environments by hydrocarbons represents a global concern with consequences on ecosystems and human health. The removal of HC by physical and/or chemical methods is expensive and disrespectful of the environment. The use of HC degrading bacteria is a good alternative for environmental remediation (bioremediation). Objectives The Algerian coastline is exposed to several types of pollutions, including hydrocarbons. The aim was to explore the bioremediation potential of its contaminated harbors for the first time. Methods To identify the hydrocarbon degrading bacteria seawater samples were collected in Sidi fredj harbor (Algeria) and used to enrichment cu…

Bacterial communities in sediment of a Mediterranean marine protected area

Biodiversity is crucial in preservation of ecosystems, and bacterial communities play an indispensable role for the functioning of marine ecosystems. The Mediterranean marine protected area (MPA) “Capo Gallo–Isola delle Femmine” was instituted to preserve marine biodiversity. The bacterial diversity associated with MPA sediment was compared with that from sediment of an adjacent harbour exposed to intense nautical traffic. The MPA sediment showed higher diversity with respect to the impacted site. A 16S rDNA clone library of the MPA sediment allowed the identification of 7 phyla: Proteobacteria (78%), Firmicutes (11%), Acidobacteria (3%), Actinobacteria (3%), Bacteroidetes (2%), Planctomyc…

Microbial bioresources for rehabilitation of natural and anthropogenic deserts

Arid lands and deserts cover one fifth of the earth’s land surface and they are currently increasing due to the global warming. Besides the natural desert settings, human activities lead to the desertification of certain areas: municipal landfills and caves are the most common examples of such anthropogenic deserts. Massive pollution and lack of natural soil profiles create harsh conditions and hinder the spontaneous rehabilitation of such areas. Phytoremediation is often used for renaturalization of such degraded soils. Two case studies are presented aiming at demonstrating that the plant-microbe interactions are essential for improving the soil quality and allowing the formation of crops.…

Differential proteomics highlights metabolic changes associated with n-hexadecane utilization in a Streptomyces coelicolor strain expressing Gordonia sp. SoCg n-alkane monooxigenase.

Introduction: Alkanes are biodegraded to generate the corresponding primary alcohol trough alkane hydroxylases (AHs) consisting on an integral membrane alkane monooxygenase (AlkB) and two soluble proteins, rubredoxin and rubredoxin reductase. Recently, an alkB gene was reported to be involved in degradation of long chain n-alkanes in the actinobacterium Gordonia sp. SoCg. This gene was expressed in Streptomyces coelicolor M145 which is unable to degrade n-alkanes. Results: The engineered strain, M145-AH, can biotransform n-hexadecane into the corresponding 1-hexadecanol and it is able to grow on n-hexadecane as sole carbon source. Changes in global protein expression associated with n-hexad…

La biodiversità dei rizobi simbionti delle leguminose legnose mediterranee come risorsa finalizzata al recupero degli ecosistemi degradati.

Comprehensive analysis of a Vibrio parahaemolyticus strain extracellular serine protease VpSP37

Proteases play an important role in the field of tissue dissociation combined with regenerative medicine. During the years new sources of proteolytic enzymes have been studied including proteases from different marine organisms both eukaryotic and prokaryotic. Herein we have purified a secreted component of an isolate of Vibrio parahaemolyticus, with electrophoretic mobilities corresponding to 36 kDa, belonging to the serine proteases family. Sequencing of the N-terminus enabled the in silico identification of the whole primary structure consisting of 345 amino acid residues with a calculated molecular mass of 37.4 KDa. The purified enzyme, named VpSP37, contains a Serine protease domain be…

So close, so different: geothermal flux shapes divergent soil microbial communities at neighbouring sites

This study is focused on the (micro)biogeochemical features of two close geothermal sites (FAV1 and FAV2), both selected at the main exhalative area of Pantelleria Island, Italy. A previous biogeochemical survey revealed high CH4 consumption and the presence of a diverse community of methanotrophs at FAV2 site, whereas the close site FAV1 was apparently devoid of methanotrophs and recorded no CH4 consumption. Next-Generation Sequencing (NGS) techniques were applied to describe the bacterial and archaeal communities which have been linked to the physicochemical conditions and the geothermal sources of energy available at the two sites. Both sites are dominated by Bacteria and host a negligib…

Gordonia sp. SoCg alkB gene confers the ability to degrade and use n-alkanes as carbon source in Gram positive bacteria

Gordonia sp. SoCg, a Gram positive strain able to grow on long chain n-alkanes1, possess a single copy of alkB2 gene, whose product is required for n-alkane hydroxylation3. An analysis of alkB flanking regions revealed five ORFs which were designed as orf1, rubA3, rubA4, rubB and alkU, according to the sequence 14 homology with that of known alk clusters3. In G. sp. SoCg the transcription of these genes was induced by long-chain and solid n-alkanes as revealed by quantitative RT-PCR, and the essential role of alkB in nalkane degradation was demonstrated by the construction of an alkB disruption mutant strain3. The SoCg alkB gene was successfully expressed in Streptomyces coelicolor M145 (M1…

Cover Crop Impact on Soil Organic Carbon, Nitrogen Dynamics and Microbial Diversity in a Mediterranean Semiarid Vineyard

Cover crop (CC) management in vineyards increases sustainability by improving soil chemical and biological fertility, but knowledge on its effects in semiarid soils is lacking. This study evaluated the effect of leguminous CC management on soil organic carbon (SOC) sequestration, soil nitrate content and microbial diversity in a semiarid vineyard, in comparison to conventional tillage (CT). SOC and nitrate were monitored during vine-growing season

AEROBIC 1,2-DICHLOROETHANE DEGRADERS IN CONTAMINATED GROUNDWATER

Interactions among rhizobial strains and arbuscular mycorrhizal fungi on Spartium junceum

Exploring methanotrophic activity in geothermal soils from Pantelleria Island (Italy)

Methane is released to the atmosphere by a wide number of natural (geological and biological) and anthropogenic sources, and is the second most important greenhouse gas after CO2. Microbial oxidation in soils by methanotrophic bacteria contributes to the removal of CH4 from the atmosphere and methanotrophic activity was also detected in volcanic/geothermal areas where degassing of endogenous gases occurs. Our aim is to describe the methanotrophs at the main exhalative area of Le Favare site at Pantelleria Island, where high CH4 consumption (up to 950 ng/g/ per h) was measured. Total soil bacterial diversity was analysed by TTGE of amplified 16S rRNA genes and the diversity of proteobacteria…

The impact of methanotrophic activity on methane emissions through the soils of geothermal areas

Methane plays an important role in the Earth’s atmospheric chemistry and radiative balance being the most important greenhouse gas after carbon dioxide. It has recently been established that geogenic gases contribute significantly to the natural CH4 flux to the atmosphere (Etiope et al., 2008). Volcanic/geothermal areas contribute to this flux, being the site of widespread diffuse degassing of endogenous gases (Chiodini et al., 2005). In such an environment soils are a source rather than a sink for atmospheric CH4 (Cardellini et al., 2003; Castaldi and Tedesco, 2005; D’Alessandro et al., 2009; 2011; 2013). Due to the fact that methane soil flux measurements are laboratory intensive, very fe…

High diversity of methanotrophic bacteria in geothermal soils affected by high methane fluxes

Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas 25 times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils act as source, but also as biological filter for methane release to the atmosphere. For long time, volcanic/geothermal soils has been considered inhospitable for methanotrophic microorganisms, but new extremophile methanotrophs belonging to Verrucomicrobia were identified in three different areas (Pozzuoli, Italy; Hell’s Gate, New Zealand; Kamchatka, Russia), explaining anomalous behaviours in methane leakages of several geothermal/volcanic sites. Our aim was to increase the know…

Impact of water stress on plant water relations, growth and mycorhization of Acacia tortilis ssp. raddiana: Interactions of the stress severity and duration, and the AM fungal species.

Mycorrhizae are commonly reported to improve drought resistance of the host plant. Investigating factors controlling the plant-resistance strategy to water stress can however lead to a suitable management of mycorrhizal plants under drought. Here, we focused on the impact of interactions of the AM fungal species and water stress severity and duration on mycorrhizal Acacia tortilis ssp. raddiana in terms of plant growth, mycorhization and water relations. We used three Glomus species, which were G. mosseae, G. deserticola and G. intraradices. We applied three watering regimes that were maximum water holding non-stress regime, mild-severe water stress and severe water stress. Measurements wer…

Integrated production of biopolymers with industrial wastewater treatment: Effects of OLR on process yields, biopolymers characteristics and mixed microbial community enrichment

The production of polyhydroxyalkanoates (PHA) using industrial wastewaters as feedstocks is a current and challenging topic. This study investigated the production of biopolymers by a mixed microbial culture under different OLRs equal to 1 kgCOD m-3d-1 (Period 1), 2 kgCOD m-3d-1 (Period 2) and 3 kgCOD m-3d-1 (Period 3). The maximum PHA content was achieved in Period 2 (0.38 gPHA gTSS-1), whereas lower values were obtained in Period 1 (0.13 gPHA gTSS-1) and Period 3 (0.26 gPHA gTSS-1). Overall, the maximum PHA productivity resulted equal to 0.08 gPHA L-1h-1 (P2), 0.05 gPHA L-1h-1 (P1) and 0.04 gPHA L-1h-1 (P3), respectively. The molecular weight of the PHA increased from Period 1 (250 kDa) t…

Methane efflux from the soil and methanotrophic activity in volcanic-geothermal areas: Examples from Italy and Greece

Isolation Of Organophosphorus Pesticides Bacteria Degraders From Agricultural Sicilian Soils.

Pesticides are generally categorized according to their great or low persistence in the environment. Although new biological, chemical, and management technologies are continually being developed to provide more sustainable production alternatives, it is expected that the use of pesticides will continue to be an essential tool in the integrated pest management. Pesticides are biologically active compounds designed to interfere with metabolic processes. Organophosphorus pesticides (OP) pesticides are less persistent than Organochlorine pesticides (OC), they are not without environmental risks, so this justifies the social concern about their level in different kind of matrices like soil, wat…

Procarioti dalle mille risorse: nuove scoperte sui metabolismi batterici che utilizzano la luce

I batteri fototrofi costituiscono un ampio ed eterogeneo gruppo di procarioti ampiamente distribuiti nel plancton marino ed i loro processi basati sulla luce sostengono e controllano il flusso di energia negli oceani. Recenti scoperte di nuovi batteri includono almeno tre modalità di fotosintesi: la fotosintesi aerobica ossigenica (tipica dei cianobatteri e simile a quella condotta dalle piante), la fotosintesi anaerobica anossigenica e la fotosintesi aerobica anossigenica (entrambe esclusive dei procarioti). Altri importanti processi basati sulla luce utilizzano le rodopsine, contribuendo così al metabolismo energetico cellulare. La fotosintesi ossigenica “pura” sembra più l’eccezione che …

Analisi della comunità batterica intestinale di larve del Punteruolo Rosso.

Le larve del Punteruolo rosso, Rhynchophorus ferrugineus (Oliv.) (Coleoptera: Curculionidae), hanno uno sviluppo endofita durante il quale innescano nella pianta fenomeni di marcescenza e di fermentazione. Quando questa attività coinvolge la gemma apicale, la pianta è destinata a soccombere. Studi condotti negli ultimi dieci anni hanno dimostrato che i microorganismi simbionti presenti nell’intestino degli insetti xilofagi giocano un ruolo chiave in diverse funzioni fisiologiche quali la digestione della cellulosa e dell’emicellulosa, l’acetogenesi, l’idrogenogenesi, la riduzione dei solfati e la fissazione dell’azoto (König et al, 2006; Khiyami e Alyamani 2008). Di conseguenza, lo studio d…

Utilizzo di Attinobatteri per la degradazione di N-alcani a catena lunga

Cloning of an alkane hydroxylase system in a long chain n-alkane- degrader Gordonia sp.

Five Gram-positive GC rich n-alkane degraders were isolated from a long-term accidentally contaminated beach in Sicily and identified as one Nocardia, two Rhodococcus and two Gordonia strains (Quatrini et al., 2008 J. Appl. Microbiol. 104:251-9). All the isolates were able to grow on long and very long chain n-alkanes up to C36. Diverging alkane-hydroxylase encoding genes (alkB) were detected by PCR using degenerated primers in all the strains. Multiple sequences were obtained from the Nocardia strain while only one alkB gene was detected in Rhodococcus and Gordonia. The aim of this work is to genetically characterize the alk cluster in one of the two Gordonia strains called SoCg. Pulsed Fi…

Isolation and characterization of Gordonia SoCg n-alkane degradation cluster

Gordonia strain SoCg is a Gram-positive GC rich n-alkane degrader, isolated from a long-term contaminated beach in Sicily for her ability to degrade long (dodecane C12) and very long chain n-alkanes up to hexatriacontane (C36) (P.Quatrini et al., J. Appl. Microbiol., 2007). PCR analysis, using degenerated primers, reveled that it carries one alkane-hydroxylase gene (alkB); PFGE and Southern analysis showed that this gene is localized on the chromosome. In order to isolate the alk cluster of Gordonia strain SoCg, an enriched gene bank was constructed in E.coli DH10B by isolating restriction fragments of the desired size from a preparative gel. One clone, containing a DNA insert of about 7 kb…

Implication of the biofilm ageing for the settlement of the vermetid gastropod Dendropoma cristatum (Biondi 1857)

Dendropoma cristatumreefs are key-intertidal habitats of the central Mediterranean. Knowledge onD. cristatumbiology is presently scant, particularly on its early life stage. The development of embryos occurs inside the maternal shell, and the crawling larvae settle on hard substrates shortly after hatching. Epilithic biofilm is known to have implications in the settlement of many marine invertebrates; however whether biofilm plays a role in driving the vermetid settlement is unknown. In this study the microbial assemblage ageing is tested as apotentialtriggerforD. cristatumsettlement. A field experiment was set-up to compare the larval settlement rate on removable limestone cubes (5x5x2 cm)…

LA BIODIVERSITÀ DEI RIZOBI SIMBIONTI DELLE LEGUMINOSE LEGNOSE MEDITERRANEE COME RISORSA FINALIZZATA AL RECUPERO DEGLI ECOSISTEMI

The microbial community of sub-surface sediment of a chronically contaminated SIC

Hydrocarbons (HC), especially high molecular weight HC, are trapped in the sediments for a long time, making the benthic system a permanent pollution source, with several effects on the biota. Sediment bacterial communities play a significant role in the degradation of contaminants, both under aerobic and anaerobic conditions. In this work we focused on the bacterial communities of sediments (5-10 cm below surface), of a Site of Community Importance, the Priolo Bay, in Central Mediterranean Sea. The bay is situated in proximity to the Augusta Harbour, affected for decades by pollution from industrial and petrochemical plants. The microbial communities of sediments from six stations on two t…

Bradyrhizobium sp. nodulating the Mediterranean shrub Spanish broom (Spartium junceum L.)

Aims: The molecular diversity of 25 strains of rhizobia, isolated in Sicily from root nodules of the Mediterranean shrubby legume Spanish broom (Spartium junceum L.), is presented in relation to the known rhizobial reference strains. Methods and Results: Our approach to the study of the S. junceum rhizobial diversity combined the information given by the 16S and the intergenic spacer (IGS) 16S–23S rDNA polymorphic region by obtaining them in a single polymerase chain reaction (PCR) step. The PCR fragment size of the S. junceum isolates was 2400–2500 bp and that of the reference strains varied from 2400 in Bradyrhizobium strains to 2800 in Sinorhizobium strains. Inter- and intrageneric lengt…

Draft genome of a novel methanotrophic Methylobacter sp. from the volcanic soils of Pantelleria Island

AbstractThe genus Methylobacter is considered an important and often dominant group of aerobic methane-oxidizing bacteria in many oxic ecosystems, where members of this genus contribute to the reduction of CH4 emissions. Metagenomic studies of the upper oxic layers of geothermal soils of the Favara Grande, Pantelleria, Italy, revealed the presence of various methane-oxidizing bacteria, and resulted in a near complete metagenome assembled genome (MAG) of an aerobic methanotroph, which was classified as a Methylobacter species. In this study, the Methylobacter sp. B2 MAG was used to investigate its metabolic potential and phylogenetic affiliation. The MAG has a size of 4,086,539 bp, consists …

Interazione fra funghi micorrizici e piante pioniere in ambienti aridi e degradati: il caso di Lampedusa

I microrganismi del suolo sono una componente dominante in diversi ecosistemi sia in termini di diversità che di funzioni. Le simbiosi microbiche radicali in particolare sono state studiate più in dettaglio negli ambienti forestali, dove si è accertato il loro ruolo nell’aumentare la capacità degli alberi di accedere ai nutrienti, sequestrare C dall’atmosfera e resistere agli effetti del cambiamento climatico. Ancora poche informazioni esistono riguardo a queste interazioni in ambienti più aridi e degradati e per le specie pioniere che innescano i processi di successione secondaria. Nell’ambito di un Progetto LIFE finalizzato a mettere a punto tecniche di adattamento al cambiamento climatic…

Preliminary results of EOLIFE99, a project concerning the conservation of four endangered plant species of Aeolian Archipelago (South Tyrrhenian Sea, Italy)

Changes in the bacterial community of Canary island date palm tissues attacked by Rhynchophorus ferrugineus (Coleoptera: Curculionidae).

The red palm weevil (RPW), Rhynchophorus ferrugineus is a trunk tissue borer that has recently become the major pest of palms in the Mediterranean Basin. In Sicily the red palm weevil is strongly associated with the Canary island date palm, Phoenix canariensis Hortorum ex Chabaud, an ornamental palm with high economic value. RPW larvae consumes the trunk tender soft tissues, making galleries that present a chewed appearance with a characteristic fermented odour. Several aspects of the RPW’s biology still need to be investigated such as its gut bacterial community, and the agents of fermentation processes that occur in the galleries made by the larvae. The aim of this work was to analyse the…

A single-chamber membraneless microbial fuel cell exposed to air using Shewanella putrefaciens

Abstract Microbial Fuel Cells (MFCs) are bio-electrochemical devices which convert the chemical energy content of organic fuels into electricity, thanks to the ability of anode respiring bacteria to give electrons to the anode. This result is usually achieved under anaerobic conditions, obtained with a sealed anode chamber. Despite this, Shewanella oneidensis has been recognized by many authors to obtain the same results in presence of air. Furthermore, another member of the Pseudomonaceae family, Shewanella putrefaciens, has also shown the capability to catalyze the cathodic oxygen reduction. In this work the capability of S. putrefaciens to work under both anaerobic and micro-aerobic cond…

Microbiological evidences of methanotriphic activity in the soils of the geothermal area of Pantelleria island (Italy)

Methane plays an important role in the Earth’s atmospheric chemistry and radiative balance being the second most important greenhouse gas after carbon dioxide. Methane is released to the atmosphere by a wide number of sources, both natural and anthropogenic, with the latter being twice as large as the former. It has recently been established that significant amounts of geological methane, produced within the Earth’s crust, are currently released naturally into the atmosphere. Active or recent volcanic/geothermal areas represent one of these sources of geological methane. Microbial oxidation in soils contributes for about 3-9% to the total removal of CH4 from the atmosphere. Recent studies e…

4-chlorobenzoate degrading Arthrobacter strains

The gut microbiota structure of the terrestrial isopod Porcellionides pruinosus (Isopoda: Oniscidea)

We used a combination of culture-dependent and independent approaches to study in depth the microbial community associated with the digestive tract of the terrestrial isopod Porcellionides pruinosus (Brandt, 1833). Specimens from different sampling sites in Tunisia harbored distinct microbiota profiles indicating the impact of both host origin and environmental factors on shaping the microbial flora within P. pruinosus. Our results revealed unexpected bacterial diversity especially via metagenomic analysis; a total of 819 operational taxonomic units (OTUs) assigned to two major bacterial phyla; Proteobacteria and Bacteroidetes. We used Nutrient Agar to isolate the cultivable fraction of bac…

Phenotypic and genotypic characterization of root nodules rhizobia of Medicago littoralis Rhode and Melilotus indicus (L.) All. growing in the Oasis of Touggourt, Oued Righ Valley, in the Algerian Sahara

Forty rhizobial strains were isolated from root nodules of Medicago littoralis Rhode and Melilotus indicus (L.) harvested from the sandy soils of Touggourt’s oases in the Oued Righ Valley, Algerian Sahara. The isolates were studied for their cultural, biochemical and symbiotic effectiveness. All of them were fast-growing bacteria; utilized a wide range of carbon sources, produced abundant extracellular polysaccharides, tolerated high concentrations of NaCl (up to 2.5 %), grew at temperatures between 28 and 45 °C and at pH values between 4.5 and 9. The isolates were sensitive to the antibiotics kanamycin, tetracycline and rifampicin but showed resistance to neomycin and erythromycin. All the…

Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)

Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a−1 (t a−1). Laboratory incubation experiments with three top-soil samples from …

Flos Tectorii degradation of mortars: An example of synergistic action between soluble salts and biodeteriogens

Abstract The definition of Flos Tectorii, originally suggested by F.S. Brancato in the 1980s’ (Brancato, 1986), refers to a unique form of deterioration identified on both aerial and hydraulic mortars used in the external walls of historic and contemporary buildings. It is clearly recognizable due to the development of peculiar concentric (occasionally sub-circular) macroscopic forms. At present, there is still a lack of information about the full interpretation of this phenomenon regarding the interaction between the different physicochemical and biological factors that lead to this particular type of degradation. The present study was aimed to examine whether the specific mineralogical an…

Le leguminose arbustive della macchia mediterranea per la rinaturalizzazione delle discariche

Le proteine ed il loro metabolismo

Evaluation in microcosm of biostimulation and bioaugmentation efficacy on diesel-contaminated soil

Bioremediation is a promising technology for the treatment of hydrocarbon (HC) contaminated soils that is based on the biodegradation capacities of native or introduced microbial populations. Biotractability tests are essential for choosing the optimal bioremediation treatment. For this purpose, multiple microcosm tests, based on biostimulation by landfarming or bioventing and addition of nutrients, were conducted for 120 days on a soil contaminated by diesel, after assessing its intrinsic catabolic potential. An additional bioaugmentation treatment was performed for further 60 days by inoculating selected HC degrading bacteria. HC (C10-C40) concentration was monitored by GC-FID analysis an…

Conquiste e frontiere biotecnologiche per l'uomo

Scienze Naturali

Il corso è stato progettato per disporre di tutti gli argomenti previsti da programma ministeriale per il quinto anno dei Licei (Chimica organica, Genetica, Biochimica, Microbiologia, Biotecnologie e Scienze della Terra) in un unico volume. Gli argomenti proposti sono trattati in maniera organica, evidenziando i possibili punti di contatto tra le differenti discipline e abituando lo studente a sviluppare una concezione liquida del sapere. La didattica e la struttura proposte sono finalizzate alla conoscenza e alla comprensione dei fenomeni che contraddistinguono la materia, la natura, gli esseri viventi e l’uomo e l’ambiente nel quale vive e col quale interagisce. Il corso concorre alla cos…

Rehabilitation of Mediterranean anthropogenic soils using symbiotic wild legume shrubs: Plant establishment and impact on the soil bacterial community structure.

Abstract Susceptibility to desertification in southern Europe is increasing and rehabilitation of desertification-threatened Mediterranean soils is a challenge due to the inhospitality of the environment. In particular, recovery of anthropogenic soils (mainly human-derived artefacts from housing construction and other inert materials or topsoil of terminal phase municipal landfills) cannot rely on spontaneous processes and low-cost/low-impact strategies are needed to prevent desertification. Mediterranean wild legume shrubs have great potential for soil recovery and conservation against desertification, thanks to drought resistance, and their symbiosis with N2-fixing rhizobia and arbuscular…

Oil-degrading bacteria from a membrane bioreactor (BF-MBR) system for treatment of saline oily waste: Isolation, identification and characterization of the biotechnological potential

A collection of forty-two (42) strains was obtained during microbiological screening of a Membrane Bioreactor (MBR) system developed for the treatment of saline oily waste originated from marine transportation. The diversity of the bacterial collection was analyzed by amplification and sequencing of the 16S rRNA gene. Taxonomic analysis showed high level of identity with recognized sequences of seven (7) distinct bacterial genera (Alcanivorax, Erythrobacter, Marinobacter, Microbacterium, Muricauda, Rhodococcus and Rheinheimera). The biotechnological potential of the isolates was screened considering an important factor such as the biosurfactant production. In particular fourteen (14) biosur…

Investigation of the methanotrophic activity in the soils of a geothermal site of Pantelleria Island (Italy)

Effetti sulla comunità batterica di un suolo contaminato indotti dalla crescita di leguminose inoculate con rizobi e funghi Micorizzici: Analisi "Culture Independent" ed isolamenti su piastra

The beta-glucosidase-encoding gene from yeast strains isolated from sicilian musts and wines.

Greenhouse gas as a nutrient: methanotrophic activity in soils of hydrothermal systems

Methane is the most abundant hydrocarbon in the atmosphere and a significant contributor to the radiative forcing with a global warming potential about 21 times that of CO2. Methane is released to the atmosphere by a wide number of sources, both natural and anthropogenic, with the latter being twice as large as the former. Significant amounts of geological methane, produced within the Earth’s crust (e.g. volcanic/geothermal areas), are currently released into the atmosphere (48 Tg CH4/y). Microbial oxidation in soils by methanotrophic bacteria contributes to the removal of CH4 from the atmosphere for about 3-9%. Methanotrophs belong to the Gamma- and Alpha-proteobacteria and to the recently…

Temporal dynamic of biofilms enhances the settlement of the central-Mediterranean reef-builder Dendropoma cristatum (Biondi, 1859).

Abstract Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum. To elucidate settlement-related biofilm features, here we analyse the structure and composition of marine biofilms over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm coverage on the substratum and the reduction of th…

Innovative, ecofriendly biosorbent-biodegrading biofilms for bioremediation of oil- contaminated water.

Immobilization of microorganisms capable of degrading specific contaminants significantly promotes bioremediation processes. In this study, innovative and ecofriendly biosorbent-biodegrading biofilms have been developed in order to remediate oil-contaminated water. This was achieved by immobilizing hydrocarbon-degrading gammaproteobacteria and actinobacteria on biodegradable oil-adsorbing carriers, based on polylactic acid and polycaprolactone electrospun membranes. High capacities for adhesion and proliferation of bacterial cells were observed by scanning electron microscopy. The bioremediation efficiency of the systems, tested on crude oil and quantified by gas chromatography, showed that…

A new scaffold-bacteria-based system for bioremediation of oil contaminated water

Bioremediation is a promising non-invasive and cost-effective technology that uses (micro)organisms to degrade or remove hazardous environmental pollutants. New methods are needed to enhance and optimize natural biodegradation, such as the use of carrier materials that could improve survival and catalytic activity of the biodegraders. In this study, we developed a bioremediation system based on a new 3D polycaprolactone-based scaffold and hydrocarbon(HC)-degrading bacteria to clean (sea)water contaminated by crude oil and its derivatives. Scaffold biopolymers are biodegradable, produced in the melt, i.e. at low cost and without the use of toxic solvents. They can be available in large quant…

Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿

ABSTRACT Enzymes involved in oxidation of long-chain n -alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n -alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n -alkanes from dodecane (C 12 ) to hexatriacontane (C 36 ) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4…

L’uso di piante mediterranee per salvare i suoli marginali o a rischio desertificazione.

Arbuscular mycorrhizal fungi positively affect growth of Ailanthus altissima (Mill.) Swingle seedlings and show a strong association with this invasive species in Mediterranean woodlands

Arbuscular mycorrhizal fungi (AMF) may promote plant invasion by enhancing plant performance and competitiveness. However, only a small number of studies have considered the interactions between local soil microbial communities and invasive plants, and even fewer have focused on alien trees. Ailanthus altissima is a serious problem in the Mediterranean Basin, where it has invaded many habitats. We investigated the symbiosis between A. altissima and indigenous AMF in two invaded, ecologically different Mediterranean woodlands. Mycorrhizal infection was high at both sites (> 60% of the root fragments were mycorrhizal), indicating that A. altissima roots may be infected by AMF under different …

Key features of bacterial communities in Southern Europe soils vulnerable to desertification

Mediterranean soils are experiencing increasingly negative effects of climate change due to drought and extreme weather phenomena that negatively affect agriculture, already suffering social and economic constraints. The LIFE project DESERT-ADAPT - Preparing desertification areas for increased climate change - (http://www.desert-adapt.it/index.php/en/) focuses on agricultural adaptation measures aimed at reverting ongoing desertification trends, while improving the socioeconomic conditions of farmers. The soil microbiota is recognized as key player in both diversity and productivity of terrestrial ecosystems and it is mandatory to include its role in sustainable agronomic management. In ord…

Struttura e funzione della cellula procariote

The role of Plant Growth Promoting (PGP) bacteria in the growth of Mediterranean diet plants producing high-value compounds

Loss of fertility, together with drought and aridity, results in soil unproductivity and eventually desertification. Unsustainable agricultural practices are currently stressing the soil: an undervalued resource that, in addition to food, provides a multitude of invaluable services such as regulating the microclimate, reducing contaminants, and capturing CO2. Hence, there is an increasing need to resort to sustainable approaches toward agricultural systems. Although Sicily is one of those regions most affected by water shortages, it is at the same time a reservoir of drought-resistant Mediterranean plants with high nutritional value and a rich microbiota. This project aims to promote agricu…

Intrinsic bioremediation potential of a chronically polluted marine coastal area.

A microbiological survey of the Priolo Bay (eastern coast of Sicily, Ionian Sea), a chronically polluted marine coastal area, was carried out in order to discern its intrinsic bioremediation potential. Microbiological analysis, 16S rDNA-based DGGE fingerprinting and PLFAs analysis were performed on seawater and sediment samples from six stations on two transects. Higher diversity and variability among stations was detected by DGGE in sediment than in water samples although seawater revealed higher diversity of culturable hydrocarbon-degrading bacteria. The most polluted sediment hosted higher total bacterial diversity and higher abundance and diversity of culturable HC degraders. Alkane- an…

Critical range of soil organic carbon in southern Europe lands under desertification risk.

Soil quality is fundamental for ecosystem long term functionality, productivity and resilience to current climatic changes. Despite its importance, soil is lost and degraded at dramatic rates worldwide. In Europe, the Mediterranean areas are a hotspot for soil erosion and land degradation due to a combination of climatic conditions, soils, geomorphology and anthropic pressure. Soil organic carbon (SOC) is considered a key indicator of soil quality as it relates to other fundamental soil functions supporting crucial ecosystem services. In the present study, the functional relationships among SOC and other important soil properties were investigated in the topsoil of 38 sites under different …

Geothermal Gases Shape the Microbial Community of the Volcanic Soil of Pantelleria, Italy

The Favara Grande nature reserve on the volcanic island of Pantelleria (Italy) is known for its geothermal gas emissions and high soil temperatures. These volcanic soil ecosystems represent “hot spots” of greenhouse gas emissions. The unique community might be shaped by the hostile conditions in the ecosystem, and it is involved in the cycling of elements such as carbon, hydrogen, sulfur, and nitrogen. Our metagenome study revealed that most of the microorganisms in this extreme environment are only distantly related to cultivated bacteria. The results obtained profoundly increased the understanding of these natural hot spots of greenhouse gas production/degradation and will help to enrich …

Patterns of soil microbial biomass and diversity across Mediterranean agroecosystems in areas under desertification risk

The gut microbiota of the wood-feeding termite Reticulitermes lucifugus (Isoptera; Rhinotermitidae)

Termite gut is host to a complex microbial community consisting of prokaryotes, and in some cases flagellates, responsible for the degradation of lignocellulosic material. Here we report data concerning the analysis of the gut microbiota of Reticulitermes lucifugus (Rossi), a lower termite species that lives in underground environments and is widespread in Italy, where it causes damage to wood structures of historical and artistic monuments. A 16S rRNA gene clone library revealed that the R. lucifugus gut is colonized by members of five phyla in the domain Bacteria: Firmicutes (49 % of clones), Proteobacteria (24 %), Spirochaetes (14 %), the candidatus TG1 phylum (12 %), and Bacteroidetes (…

Biodiversity of organophosphorus-degrading bacteria isolated from agricultural soils

Organophosphorus (OP) insecticides are used all over the world for crop protection. Although OPs are less persistent than organochlorine pesticides, they still constitute an environmental risk thus increasing the social concern about their levels in soils, surface and ground waters. Biodegradation by microorganisms is primarily responsible for elimination of the OP insecticides released to the environment. In the present study the OP degrading potential of agricultural soils with different agronomic history was investigated. Using enrichment cultures, with parathion or dimethoate as the sole C and energy sources, 47 bacterial isolates were obtained from OPs contaminated and pristine agricul…

Identification of a large circular plasmid in Arthrobacter ramosus FG1 encoding the dechlorination of 4-chlorobenzoate

DIVERSITÀ BATTERICA DI SUOLI MEDITERRANEI SOGGETTI A DESERTIFICAZIONE

Siccità e fenomeni meteorologici estremi contribuiscono al degrado dei suoli mediterranei semi-aridi causando erosione, compattazione, salinizzazione, riduzione della sostanza organica e perdita di biodiversità, con conseguenze negative per l’agricoltura e l’ambiente. Gli effetti dei cambiamenti climatici in atto sono esacerbati da pratiche agronomiche insostenibili e pascolo incontrollato che concorrono alla desertificazione dei suoli. E’ fondamentale monitorare la qualità dei suoli semi-aridi per prevenirne il degrado irreversibile. Tale monitoraggio viene usualmente condotto mediante i tradizionali indicatori chimico-fisici di qualità del suolo. Ancora raramente vengono utilizzati indica…

Abatement of AO7 in a divided microbial fuel cells by sequential cathodic and anodic treatment powered by different microorganisms

Abstract Microbial fuel cells (MFCs) can allow the treatment of organic pollutants resistant to conventional biological processes by electro-Fenton (EF) process performed in the cathodic compartment. However, EF usually results in a partial mineralization of pollutants. Here, we have studied the possible treatment of such organics in a MFC by a sequential cathodic and anodic treatment. In particular, the treatment of an aqueous solution of Acid Orange (AO7), a largely used azoic dye resistant to conventional biological processes, was performed in the cathodic compartment of a divided MFC by EF. The process allowed the total removal of the color and the partial removal of the TOC, due mainly…

Identification of a large catabolic plasmid in Arthrobacter ramosus FG1

Polycaprolactone-based scaffold for oil-selective sorption and improvement of bacteria activity for bioremediation of polluted water: Porous PCL system obtained by leaching melt mixed PCL/PEG/NaCl composites: Oil uptake performance and bioremediation efficiency

A novel floatable and biodegradable sponge for the selective absorption of oil from water and potentially useful as cell carrier for bioremediation treatments was prepared in polycaprolactone (PCL). The eco-friendly process for fabricating the PCL sponge does not involve either synthetic routes or organic solvents, thus minimizing environmental hazard. In particular, the 3D porous materials have been prepared by mixing in the melt the polymer matrix with two water-soluble porogen agents (NaCl and PEG) and thereafter leaching the obtained PCL/NaCl/PEG composites in water. The PCL sponges here proposed are capable to remove different types of oily pollutants (up to 500 wt%), and were successf…

Gram positive long chain n-alkane degraders from a hydrocarbon contaminated Sicilian shoreline.

SIMBIONTI RADICALI DI ASTRAGALUS NEBRODENSIS (GUSS.) STROBL.

Le leguminose spontanee mediterranee hanno un elevato potenziale nei processi di rinaturalizzazione di ecosistemi degradati o semiaridi poiché stabiliscono simbiosi radicali con batteri azoto-fissatori e funghi micorrizici i quali, agendo sinergicamente, avvantaggiano la pianta per la nutrizione e la resistenza agli stress. Astragalus nebrodensis è un arbusto perenne appartenente alla famiglia delle Fabaceae, endemico in Sicilia; i simbionti radicali di questa specie non sono noti. Gli obiettivi di questo studio sono stati: 1) l’analisi della diversità dei rizobi simbionti di Astragalus nebrodensis; 2) la valutazione dell’effetto dell’inoculo di rizobi da collezione e di funghi micorrizici …

1,2-DICHLOROETHANE CONTAMINATED AQUIFER: MICROBIAL COMMUNITY RESPONSE TO BIOSTIMULATION IN MICROCOSM

Combining ecological engineering and plant conservation on a Mediterranean islet

This paper reports the results of a bioengineering intervention within the Mediterranean Basin carried out at Lampedusa Island (Strait of Sicily) on the “Spiaggia dei Conigli”, the only sand shore of all Sicilian territory where the sea turtle Caretta caretta lays its eggs every year. The erosion of the steep slope over the beach itself caused sensitive changes in the grain size of shore’s sediment and reduced the area of the beach with fine sand suitable for C. caretta oviposition. In order to reduce surface water flow and to stop erosion, several bioengineering options were adopted using only native plant species to preserve local botanical heritage and to prevent the local extinction of …

Metagenome Assembled Genome of a Novel Verrucomicrobial Methanotroph From Pantelleria Island.

Verrucomicrobial methanotrophs are a group of aerobic bacteria isolated from volcanic environments. They are acidophiles, characterized by the presence of a particulate methane monooxygenase (pMMO) and a XoxF-type methanol dehydrogenase (MDH). Metagenomic analysis of DNA extracted from the soil of Favara Grande, a geothermal area on Pantelleria Island, Italy, revealed the presence of two verrucomicrobial Metagenome Assembled Genomes (MAGs). One of these MAGs did not phylogenetically classify within any existing genus. After extensive analysis of the MAG, we propose the name of “Candidatus Methylacidithermus pantelleriae” PQ17 gen. nov. sp. nov. The MAG consisted of 2,466,655 bp, 71 contigs …

Plastica in mare: biodiversità della plastisfera

La plastica costituisce la componente più abbondante dei rifiuti in ambiente marino. Le plastiche in mare sono colonizzate da biofilm microbici, denominati plastisfera, che possono comprendere patogeni, specie algali tossiche e invasive e, potenzialmente, organismi in grado di biodeteriorare e degradare le plastiche (Zettler et al. 2013). Lo scopo di questo lavoro è studiare e confrontare le comunità microbiche che colonizzano plastiche biodegradabili e non biodegradabili in ambiente marino. Un esperimento di esposizione di film plastici in ambiente marino portuale è stato allestito per studiare la diversità della plastisfera di alcune plastiche biodegradabili (Mater Bi e PLA-acido polilatt…

Microbial communities and novel taxa in « Continental Smokers » of northern Greece

Analogously to the ocean-bottom black/white smokers, “continental smokers” have recently been defined as sites of mantle degassing through continental crust. The goal of this research, carried out within the Deep Carbon Observatory Community, is to investigate the role of deeplysourced fluids in niche ecosystem differentiation in European continental smokers. A 16S rRNA gene survey of microbial communities was carried out on 11 geothermal manifestations of northern Greece, all showing a distinct contribution of mantle fluids (R/Ra up to 1.2) that allow to classify them as continental smokers. The selected sites cover a wide range of temperatures (15-77 °C), pH (6.11-8.46), Eh (-289 – 40 mV)…

Evaluation of benefits and limitations of a Desertification Adaptation Model framework for sustainable land management in areas under desertification risk

The LIFE project Desert-Adapt (LIFE16 CCA/IT/000011) has designed a Desertification Adaptation Model (DAM) framework of land management to respond to two of the most critical problems experienced by farmers, public land and communities of the Mediterranean Basin, given the need to adapt to current Climate Change and reduce or counteract the increasing phenomenon of land degradation and desertification risk. These two issues are interrelated, as land degradation often characterizes fragile areas where the co-occurrence of climatically unfavourable conditions, mostly prolonged aridity and high temperatures, and inappropriate land management, leads to loss of ecosystem quality, biodiversity, p…

Metagenomic analysis of the microbiota hindgut of Reticulitermes lucifugus (Rossi) (Isoptera: Rhinotermitidae)

Termites hindguts host a microbial community consisting of anaerobic flagellates and bacteria. This gut microflora is responsible for the degradation of lignocellulosic material. Here we report the data concerning the analysis of the hindgut microbial community of Reticulitermes lucifugus (Rossi), a termite commonly present in Italy, based on a metagenomic approach. Metagenomic DNA was extracted from the gut content of termites and the SSU rDNA was polymerase chain reaction (PCR) - amplified using universal primers for prokaryotes and eukaryotes. Two clone libraries were constructed and clones were grouped into Operational Taxonomic Units (OTU) by RFLP analysis. One representative clone was…

I lipidi ed il loro metabolismo

Soil microbial biomass and bacterial diversity in southern European regions vulnerable to desertification

Abstract Soil functionality is strongly dependent on the soil microbiota, which in turn is affected by soil quality and climate. Among global change factors, desertification is the most threatening ecosystem change affecting southern Europe, but the effects on the soil microbiota are largely unknown. In this study, we investigated soil microbial biomass and bacterial diversity in regions of southern European countries (Spain, Portugal and Italy), most under desertification risk, and related to key soil chemical-physical indicators and land use. Soil microbial biomass was positively related, to soil organic carbon (SOC) but bacterial diversity was negatively correlated with it. pH was the mo…

Hydrocarbon degrading bacteria vs microbial consortia in the degradation of Policyclic Aromatic Hydrocarbons

The Harbor of Priolo Gargallo is a chronically polluted area in Sicily (Italy). Bioremediation is an alternative friendly strategy to reduce environmental risks that relies on microorganisms that play a key role in the biodegradation of hydrocarbon contaminants. In this study, sediment samples were collected in 6 stations inside the area indicated. Analysis of total hydrocarbons, microbial abundance (DAPI, CFU and MPN), and total bacterial diversity (DGGE) were carried out. Enrichment cultures and isolation of hydrocarbon-degrading bacteria were carried out in the mineral medium ONR7a with a mix of Polycyclic Aromatic Hydrocarbons [PAHs-Mix; Methylnaphtalene, Byphenile, Phenantrene, Dibenzo…

Microbiology meets geochemistry: geothermal flux shapes different microbial communities at the same exhalative area

Volcanic/geothermal areas are sites of complex interactions between geosphere and biosphere. Pantelleria island (Southern Mediterranean Sea) hosts a high enthalpy geothermal system characterized by high CH4 and low H2S fluxes. Two sites, FAV1 and FAV2, located a few meters apart at the main exhalative area of the island (Favara Grande), recorded similar physical conditions (soil temperature 60°C, soil gas composition enriched in CH4, H2 and CO2). However, while high methanotrophic activity (59.2 nmol g-1 h-1) and high diversity of methanotrophs was detected at FAV2, FAV1 was not active and appeared deprived of methanotrophs (1). Our aim was to investigate the main factors influencing methan…

Biodegradation of organophosphorus pesticides by soil bacteria.

A number of studies in the 1980s and 1990s showed that crop-protection products, applied to drained fields, could move downwards through the soil profile and to the groundwater. Organophosphorus insecticides (OPs) are used all over the world for crop protection, for other agricultural practices such as sheep dipping and, in aquaculture, for the control of sea lice. Ops besides showing a specific neurotoxicity and have also been related to various modern diseases, including Creutzfeldt–Jakob (CJD) and the Gulf War syndrome. Although OPs are less persistent than Organoclorine pesticides (OCs), they still constitute an environmental risks thus increasing the social concern about their levels i…

The paradox of the alien plant Leucaena leucocephala subsp. glabrata (Rose) S. Zárate in Sicily: another threat for the native flora or a valuable resource?

With this contribution, an updated picture of the rapid expansion of Leucaena leucocephala subsp. glabrata in Sicily is provided. On the one hand, this is a quite worrying sign, as this woody species figures among the world’s worst invasive alien species. On the other hand, the species shows interesting potential for production purposes (for wood, biomass and for feeding livestock), also considering its nitrogen fixation ability. Consequently, the two opposite options to cope with this species, i.e. cultivation and control/eradication, should accurately take into account the possible uses as well as its invasive behaviou.

Isolation and Characterization of Oil-Degrading Bacteria from Bilge Water

Twenty-one oil-degrading bacteria were isolated from bilge water. Based on a high growth rate on crude oil and on hydrocarbon degradation ability, 7 strains were selected (from 21 isolated) for further studies. 16S rRNA gene sequencing showed that isolated strains were affiliated to Bacillus, Pseudomonas and Halomonas genera; in particular, isolate BW-B12 (Bacillus sp., 99%), BW-C12 (Halomonas boliviensis, 99%) and BW-E12 (Halomonas boliviensis, 98%) were the best crude-oil degraders; after 10 days of cultivation in ONR 7a mineral medium supplemented with crude oil as single carbon source BW-B12, BW-C12 and BW-E12 showed a degradation rate of 80, 60 and 59%, respectively. The strains showed…