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

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…

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…

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 …

Chemical composition, cytotoxic effects, antimicrobial and antibiofilm activity of Artemisia arborescens (Vaill.) L. growing wild in the province of Agrigento, Sicily, Italy

Artemisia arborescens (Vaill.) L. is a perennial shrubby plant growing along the coastal strips of the Mediterranean region. It is used in traditional medicine. Its essential oil and solvent extracts exhibit a very interesting chemotherapeutic potential, which makes this plant useful in maintaining human health. The goal of this study was to determine the phytochemical composition of the petroleum ether and methanol extracts, as well as to evaluate anticancer activities and antimicrobial and biofilm formation reduction. Thirty-nine phytochemical compounds in negative ion mode, and 25 in positive ion mode were identified by HPLC-ESI-QTOF-MS. All four extracts reduced the viability of human M…

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…

An asymmetric electrospun membrane for the controlled release of ciprofloxacin and FGF-2: Evaluation of antimicrobial and chemoattractant properties.

Here, an asymmetric double-layer membrane has been designed and fabricated by electrospinning as a tool for a potential wound healing application. A hydrophobic layer has been produced by using a polyurethane-polycaprolactone (PU-PCL) copolymer and loaded with the antibacterial ciprofloxacin whereas an ion responsive hydrophilic layer has been produced by using an octyl derivative of gellan gum (GG-C8) and polyvinyl alcohol (PVA) and loaded with the growth factor FGF-2. This study investigated how the properties of this asymmetric membrane loaded with actives, were influenced by the ionotropic crosslinking of the hydrophilic layer. In particular, the treatment in DPBS and the crosslinking i…

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…

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…

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…

Phytochemical-rich extracts of Helianthemum lippii possess antimicrobial, anticancer, and anti-biofilm activities

Helianthemum lippii is a perennial shrubby plant growing in the sandy environments of Italy, Mediterranean countries of North Africa and Middle East. H. lippii is used in traditional medicine but there are very few reports referring to the phytochemical characterization, the ethnopharmacology, and the biological activity of H. lippii. The goal of this study was todetermine the phytochemical composition of different H. lippii extracts, cold (CME) and hot (HME) methanol, cold (CPEE) and hot (HPEE) petroleum ether, as well as to evaluate their anticancer and antimicrobial activities and biofilm formation reduction. Fifty-fours phytocompounds have been determined by HPLC-UV-ESI-QTOF-MS analysis…

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 …

Photothermal nanofibrillar membrane based on hyaluronic acid and graphene oxide to treat Staphylococcus aureus and Pseudomonas aeruginosa infected wounds.

Here we reported the fabrication of an electrospun membrane based on a hyaluronic acid derivative (HA-EDA) to be used as a bandage for the potential treatment of chronic wounds. The membrane, loaded with graphene oxide (GO) and ciprofloxacin, showed photothermal properties and light-triggered drug release when irradiated with a near-infrared (NIR) laser beam. Free amino groups of HA-EDA derivative allowed autocrosslinking of the elec- trospun membrane; thus, a substantial enhancement in the hydrolytic resistance of the patch was obtained. In vitro antibacterial activity studies performed on Staphylococcus aureus and Pseudomonas aeruginosa revealed that such electrospun membranes, due to the…

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…

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…

Procedimento per la biodegradazione di oli e/o grassi esausti

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…

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…

New Bioactive Peptides from the Mediterranean Seagrass Posidonia oceanica (L.) Delile and Their Impact on Antimicrobial Activity and Apoptosis of Human Cancer Cells

The demand for new molecules to counter bacterial resistance to antibiotics and tumor cell resistance is increasingly pressing. The Mediterranean seagrass Posidonia oceanica is considered a promising source of new bioactive molecules. Polypeptide-enriched fractions of rhizomes and green leaves of the seagrass were tested against Gram-positive (e.g., Staphylococcus aureus, Enterococcus faecalis) and Gram-negative bacteria (e.g., Pseudomonas aeruginosa, Escherichia coli), as well as towards the yeast Candida albicans. The aforementioned extracts showed indicative MIC values, ranging from 1.61 μg/mL to 7.5 μg/mL, against the selected pathogens. Peptide fractions were further analyzed thr…

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…

Enzymatic Synthesis and Antimicrobial Activity of Oligomer Analogues of Medicinal Biopolymers from Comfrey and Other Species of the Boraginaceae Family

This study reports the first enzymatic synthesis leading to several oligomer analogues of poly[3-(3,4-dihydroxyphenyl)glyceric acid]. This biopolymer, extracted from plants of the Boraginaceae family has shown a wide spectrum of pharmacological properties, including antimicrobial activity. Enzymatic ring opening polymerization of 2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane (MDBPO) using lipase from Candida rugosa leads to formation of poly[2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane] (PMDBPO), with a degree of polymerization up to 5. Catalytic debenzylation of PMDBPO using H2 on Pd/C yields poly[2-methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane] (PMDHPO) without loss in molecul…

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…

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…

A Novel Peptide with Antifungal Activity from Red Swamp Crayfish Procambarus clarkii

The defense system of freshwater crayfish Procambarus clarkii as a diversified source of bioactive molecules with antimicrobial properties was studied. Antimicrobial activity of two polypeptide-enriched extracts obtained from hemocytes and hemolymph of P. clarkii were assessed against Gram positive (Staphylococcus aureus, Enterococcus faecalis) and Gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and toward the yeast Candida albicans. The two peptide fractions showed interesting MIC values (ranging from 11 to 700 μg/mL) against all tested pathogens. Polypeptide-enriched extracts were further investigated using a high-resolution mass spectrometry and database search and 14 n…

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

Developing Antibiofilm Fibrillar Scaffold with Intrinsic Capacity to Produce Silver Nanoparticles

The development of biomedical systems with antimicrobial and antibiofilm properties is a difficult medical task for preventing bacterial adhesion and growth on implanted devices. In this work, a fibrillar scaffold was produced by electrospinning a polymeric organic dispersion of polylactic acid (PLA) and poly(α,β-(N-(3,4-dihydroxyphenethyl)-L-aspartamide-co-α,β-N-(2-hydroxyethyl)-L-aspartamide) (PDAEA). The pendant catechol groups of PDAEA were used to reduce silver ions in situ and produce silver nanoparticles onto the surface of the electrospun fibers through a simple and reproducible procedure. The morphological and physicochemical characterization of the obtained s…

ANTIMICROBIAL ACTIVITY FROM POLYPEPTIDE-RICH EXTRACTS OF THE SEAGRASS POSIDONIA OCEANICA

The present study was carried out to assess the antibacterial, antifungal and antibiofilm properties of polypeptide-rich extracts isolated from green leaves and rhizomes of Mediterranean seagrass Posidonia oceanica (L. Delile) (Posidoniaceae). The seagrass was collected, washed with freshwater, grinded with liquid nitrogen in order to obtain fine powders that were exposed to extraction by acetic acid and antiproteases. The crude extracts isolated from leaves and rhizomes of P. oceanica were subjected to microbiological assays to evaluate the antibacterial, antifungal and antibiofilm activity of polypeptide fraction against two reference bacterial strains Staphylococcus aureus ATCC 25923 and…

High-Performance PCR for Alleles Discrimination of Chromo-Helicase-DNA Binding Protein (CHD1) Gene in Bird Sexing

Genetic analyses aiming at assessing the presence of specific sequences or alleles are often carried out by PCR. Sexing of most birds is nowadays based on PCR with “universal” primers and relies on the assessment of the presence of the sex-linked CHD1-Z and -W alleles. The entire workflow is relatively time-consuming, especially for batch analyses, whereas methods that allow carrying out the entire procedure in a short time are highly desirable. The only method for outdoor analyses reported so far relies on LAMP; however; it fails to work properly in Procellariiformes. Besides improving the LAMP test; we have developed a PCR-based DNA amplification procedure (named high-performance PCR); wh…

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)…

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…

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…

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…

ANTIMICROBIAL AND ANTIBIOFILM ACTIVITY OF A PEPTIDE IDENTIFIED IN THE SEAGRASS POSIDONIA OCEANICA

Fabrication of silver nanoparticles by a diethylene triamine-hyaluronic acid derivative and use as antibacterial coating

In this work a synthetic protocol for the functionalization of hyaluronic acid with diethylenetriamine (DETA) was standardized. HA-DETA derivatives were characterized by NMR and proton carbon correlation analysis HSQC and HMBC to confirm chemical structure. A selected derivative was used to set up a green fabrication procedure for HA-DETA capped silver nanoparticles with the aim to achieve a polymeric based coating with potential application in the treatment of medical devices associated infections. Data from UV-visible spectroscopy, electron scanning and transmission microscope (STEM), photoelectric spectroscopy (XPS) and rheological characterization were combined to characterize the HA-DE…

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…

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…

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…

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…

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

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…

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.

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)…

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…

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.