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…

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…

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…

Thermal degradation of microcrystalline cellulose in concentrated phosphoric acid as assessed by HPLC, high field NMR spectroscopy and low field NMR relaxometry

The most common renewable fuel is ethanol. It is a liquid produced by fermentation of glucose which is very abundant in cellulose based material sources. Plants produce about 180 billion tons of cellulose per year globally. For this reason cellulose is the largest organic carbon reservoir on Earth. Cellulose is composed exclusively of glucose units linked via B-1,4 glycosidic bonds. Each D-(+)-glucose unit contains three hydroxyl groups, which can form complex spatial networks of inter- and intra- molecular hydrogen bonds. They are responsible for the high crystallinity and compactness of cellulose, thereby making it very resistant to biological and chemical attack. In the presence of miner…

Alla scoperta delle proprietà nutraceutiche dell’ olio extravergine d’oliva

Degradazione termica di biomasse lignocellulosiche in acido fosforico

La lignocellulosa è la più abbondante fonte rinnovabile per la produzione di bioetanolo. Sfortunatamente la produzione di biocarburanti liquidi da scarti lignocellulosici presenta molti inconvenienti a causa della compattezza e della complessità di questi materiali, caratteristiche che rendono molto più difficoltosa la loro degradazione enzimatica in zuccheri fermentabili rispetto ad altri biopolimeri come l’amido. Inoltre il costo della produzione di bioetanolo da biomasse lignocellulosiche è ancora molto alto rispetto a quello dei processi industriali che utilizzano come materiale di partenza l’amido. Obiettivo del presente studio è quello di testare su campioni di biomassa lignocellulosi…

Regeneration of cellulose by water addition to phosphoric acid/cellulose mixture

In the last years, phosphoric acid has been increasingly considered as a simple and economic solvent for cellulose pretreatment before its degradation to glucose. Cellulose swells in 71–80% phosphoric acid solutions, whereas at higher H3PO4 concentrations dissolution appears to occur. In addition, it is reported that regenerated cellulose is more easily fermentable to bioethanol. The aim of the present study was to elucidate the mechanism for cellulose regeneration following treatment with phosphoric acid at room temperature. CPMAS 13C NMR spectra revealed a downfield shift of the 13C NMR signals from the regenerated cellulose as compared to the crystalline one. CPMAS 31P NMR spectroscopy s…

Thermal degradation of microcrystalline cellulose in concentrated phosphoric acid

The most common renewable fuel is ethanol. It is a liquid produced by fermentation of glucose which is very abundant in cellulose based materials. Bioethanol is achieved in a two-steps process: 1. hydrolysis of the cellulose included in the ligno-cellulosic materials to fermentable reducing sugars; 2. fermentation of such sugars to ethanol. While the second fermentation step, mediated by yeasts or bacteria, is very well established, the first one must be still assessed for process optimization. Many efforts have been made to identify solvents for cellulose in order to develop methods for the achievement of fermentable glucose. In the presence of mineral acid, cellulose undergoes hydrolysis …

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…

Effect of texture on the dynamics of a water saturated biochar

Biochar is defined as charred organic matter applied to soil in a deliberate manner, with the intent to improve soil properties (Lehmann et al., 2009). Biomass-derived char can be used as energy carrier, as adsorber and as material for the improvement of soil properties. Carbonized organic matter can have different physical and chemical properties depending on the technology used for its production. Moreover char texture influences deeply physical and chemical properties. In this work effect of texture on the dynamics of a water saturated biochar was analyzed by FFC NMR. An industrial biochar derived from gasification of poplar wood was sieved to determine influence of texture on water dynami…

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…

Effect of kinematic viscosity over the dynamic properties of an extra-virgin olive oil

Previous studies 1,2 have shown that kinematic viscosity values of food oils depend on the presence of added solvents and on the nature of the oil under investigation (e.g., geographical origin and treatments prior to oil production). However, to the best of our knowledge, only one paper 3 dealt with the correlation between viscosity values and relaxation times of simple pure alkyl compounds. Up to now, no papers have been found in literature dealing with viscosity of complex mixtures and their relaxometric properties. In this study, we intended to investigate the effect of kinematic viscosity over the dynamic properties of an extra-virgin olive oil which is known as a very complex mixture …

Nuove biotecnologie: insetti e biocarburanti

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…

BIOCHAR SURFACE PROPERTIES THROUGH APPLICATION OF AN INNOVATIVE NMR TECHNIQUE: FAST FIELD CYCLING RELAXOMETRY

Biochar is a carbonaceous material obtained by pyrolysis of biomass feedstocks. It is applied to soils in order to improve fertility and mitigate greenhouse-gases emissions. In fact, from the one hand, biochar changes physical-chemical soil properties, thereby affecting soil fertility. From the other hand, biochar is resistant to chemical and biochemical degradation. For this reason, its use allows carbon sequestration in soils and consequent reduction of carbon dioxide to the atmosphere. Here, dynamics of water at the liquid-solid interface of water saturated biochars is discussed. Results revealed that water dynamics is affected by the nature of biochar parent biomasses. Moreover, biochar…