Heterotrophic psychrotolerant marine bacteria from Potter Cove producing cold-active compounds

VAZQUEZ S.; TROPEANO M.; CORIA S.; BERCOVICH A.; MAC CORMACK W.

Buenos Aires, Argentina

Congreso; XXXI SCAR and Open Science Conference; 2010

Identification of the predominant bacterial groups inhabiting a certain environment anddescription of their metabolic capabilities are helpful in the search for new biomolecules with potential industrial application. Marine bacteria from Potter Cove were identified to the genus level using physiological (API system) and molecular (16SrDNA sequencing) traits. Isolates were obtained in marine (MA, non-selective) or skim-milk (SMA, selective for proteolytic bacteria) agar. Antibacterial (ABA) and enzymatic activities (EA) and exopolysaccharide (EPS) production were tested in the isolates. Enzyme production was evidenced in media containing cellulose, CMC, xylan, pectin, skim-milk or starch as carbon source. EPS was detected by production of mucoid colonies in MA with glucose and ABA was tested against reference strains grown in overlay-agar. Among 277 isolates 13 phylotypes, belonging to 3 taxonomic groups, were detected. Their 16SrDNA sequences shared >97% identity with known type-strains except by three that could correspond to non-described species. The highest diversity was found in the gamma-Proteobacteria, Psychrobacter and Pseudoalteromonas being dominating. Phylotypes in Actinobacteria belonged to Frigoribacterium, Leifsonia and Arthrobacter genus, in Baciilli toPlanococcus and in alfa-Proteobacteria to Sulfitobacter. The highest proportion of EA+EPSproducing was Pseudoalteromonas, while Psychrobacter had few positive representatives. ABA could not be detected in any of the isolates. It was observed that production of EPS+multiple EA was more frequent in bacteria isolated in SMA than in the non-selectively isolated ones. A deeper knowledge of the features of these cold-molecules would help the genetic engineering of commercial enzymes and the search for new bioactive compounds.