Maurizio Catalfamo

Metabolic specialization is a general biological principle that shapes the assembly of microbial communities. Hydrocarbonoclastic bacteria (HCB) are marine bacteria that are specialised in hydrocarbon degradation and use hydrocarbons almost exclusively as unique C and energy source. HCB become dominant in oil-\uad\u2010impacted environments and are particularly adapted for removal of hydrocarbons from contaminated sites through bioremediation treatments. The petrochemical site of Priolo-\uad\u2010Augusta-\uad\u2010Melilli (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 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 population diversity, PCR-\uad\u2010DGGE) and chemical-\uad\u2010physical characterisation (quali-\uad\u2010, quantitative measures of hydrocarbons and heavy metals) samples were used, separately, to set enrichment cultures on mineral broth containing different mixtures of linear (C16, C18, C20) and aromatic (phenatrene, pyrene, biphenyl and dibenzothiophene) hydrocarbons and Crude Oil (Arabian Ligth Crude Oil). A total of 159 isolates (82 from seawater and 77 from sediments) were obtained. The sequencing of 16S rDNA showed the most of the isolates belonged to, Alcanivorax (44 %), Marinobacter (17%) and Oleibacter (9%) genera. Data obtained from assays of biodegradation revealed as more interesting bacteria present a very high potential of application in bioremediation techniques; furthermore data obtained give a deeper understanding of the biochemical causes of metabolic specialization and could serve as a foundation for the field of synthetic ecology, where the objective would be to rationally engineer the assembly of a microbial community to perform a desired biotransformation

Petroleum hydrocarbons are the most widespread contaminants in the marine environment. The fate of petroleum in sea water is largely controlled by mechanical, physical and chemical factors which influencing the natural transformation of petroleum (oil weathering) and oil bio-degradation. On the basis of these considerations, bioremediation techniques have been developed and improved for cleaning up oil-polluted marine environment as alternative to chemical and physical techniques. To elucidate the cooperative action of mixed microbial populations in the biodegradation of crude oil, we constructed artificial consortia composed of two to three bacteria (Alcanivorax borkumensis strain SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeriSDM) capable to degrade oil hydrocarbons. Using these consortia, we investigated the mechanism by which efficient biodegradation of crude oil could be accomplished by the mixed populations for application in natural environment (bioaugmentation). All experiments were carried out in microcosms systems containing seawater (with and without inorganic nutrients) and oil was used as sole carbon source. All data obtained (Total DAPI Count, Live/Dead staining, Card-FISH and GC-FID hydrocarbons analysis) confirmed the fundamental role of bacteria belonging to Alcanivorax genus in degradation of linear hydrocarbons in oil polluted environments. Indeed, in all experimentations carried out in seawater with or without inorganic nutrients showed as rates of oil degradation are almost total in presence of this bacterium

1Doctor School “Biologia e Biotecnologie Cellulari” University Of Messina" Microbial Resources Division" Research Center For Chemistry, Biology And Agriculture, Universidade Estadual De Campinas 2Microbial Resources Division" Research Center For Chemistry, Biology And Agriculture, Universidade Estadual De Campinas 3Department Stebicef, University Of Palermo, Italy 4Institute For Marine Coastal Environment (Iamc) Cnr U.O.S. Of Messina 5BIOREM; Neuville-En-Condroz, Belgium * e-mail: sanny.santisi@yahoo.it

The enantiomeric distribution of mandarin essential oil coming from fruits belonging to "Avana" and "Tardivo di Ciaculli" was studied. The prevalence of four dextrorotatory isomers it is a characteristic of mandarin essential oil. Composition of the volatile fraction and chemical-physical analysis complete the investigation finalized to define the variability ranges of the genuine essential oils.

A method for the determination of orange and lemon juice limonene content is reported. The method foresees an extraction-distillation (SDE) of the sample through a Likens-Nickerson apparatus followed by gaschromatographicanalysis. The data obtained have been compared with the bromide method. The chiral analysis of the limonene in orange juices has been done. These results suggest that limonene in the analyzed juices is from natural origin.

The essential oils extracted by the two cultivars were classified as "linalool type" due to their chemical compositional characteristics. The enantiomeric analysis was performed on six compounds of the essential oil (sabinene, β-pinene, limonene, linalool, 4-terpineol, α-terpineol). Among these, the linalool resulted the most abundant compound, with a enantiomeric distribution of the form (-) predominant on the (+) one, with values above 99% for both basil cultivars.

Essential oils coming from different cultivars of Sweet orange, Bitter orange and Bergamot fruits were analysed. Enantiomeric distribution (by multidimentional gascromatography), volatile fraction composition and chemical-physical analysis were carried on all samples. Variability range was defined.