Cold-Active Enzymes Bioprospecting from Actinobacteria isolated from Beagle Channel, in South Extreme of Argentina

ALVARENGA, ADRIANA ELISABETH; PEREIRA, CLAUDIA ELIZABETH; AMOROSO, MARIA JULIA; ABATE, CARLOS MAURICIO

Puerto Vallarta

Simposio; 16th International Symposium on the Biology of Actinomycetes (ISBA16): The Evolution of Actinomycetes; 2011

LANGEBIO (Laboratorio Nacional de Genómica para la Biodiversidad)

The recent discovery of novel secondary metabolites of marine actinobacteria suggests that these bacteria populations add an important dimension to research about microbial natural products. Characterization of actinobacteria diversity and their marine environment adaptations, which affects secondary metabolite production, has taken great importance. The aims of this work were isolate actinobacteria from Beagle Channel, Ushuaia, Argentina and bioprospect cold-active enzymes produced by them. For this purpose, twenty-four isolates were selected based on their morphology in different culture media. DNA extraction and 16S rRNA gene amplification using universal primers were carried out. The 16S rRNA gene of the isolates was digested by EcoRI and HpaII restriction enzymes. This allowed to separate into three different groups according to their restriction enzyme pattern. The phylogenetic analysis based on 16S rRNA gene sequencing showed that isolates belonged to Actinobacteria class and genera Rhodococcus, Microbacterium, Nocardia and Salinibacterium. Five representatives of these genera were selected for further studies. The utilization of carbon sources plays an important role in species differentiation by bacteria and also by the Actinobacteria. Different strain abilities to use carbon sources (glucose, arabinose, sucrose, xylose, inositol, mannitol, fructose, rhamnose, raffinose, cellulose) were showed. More than a half of isolates were pigmented. All the strains were able to grow in a wide range of temperature (4-37 ºC) and pH (2-10). Also, the isolates showed NaCl tolerance (0.1-1 M). After that, isolates were screened for α-L-rhamnosidase, xylanase, cellulose, β-glucosidase, amylase, lipase and protease activities at 4 and 20 ºC. All selected isolates showed α-L-rhamnosidase activity under the assayed conditions. These results have given evidence of the utility of these bacteria as a source of useful products for biotechnology.