Cold-active enzymes bioprospecting from Actinobacteria isolated from Beagle channel, in south extreme of Argentina

ALVARENGA, A.E; PEREIRA, E.C.; AMOROSO M.J.; ABATE, C.M.

Puerto Vallarta

Congreso; 16th International Symposium on the Biology of Actinomycetes (ISBA16).; 2011

The recent discovery of novel secondary metabolites of marine actinobacteriasuggests that these bacteria populations add an important dimension toresearch about microbial natural products. Characterization of actinobacteriadiversity and their marine environment adaptations, which affects secondarymetabolite 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 morphologyin different culture media. DNA extraction and 16S rRNA gene amplificationusing universal primers were carried out. The 16S rRNA gene of the isolateswas digested by EcoRI and HpaII restriction enzymes. This allowed to separateinto three different groups according to their restriction enzyme pattern. Thephylogenetic analysis based on 16S rRNA gene sequencing showed thatisolates belonged to Actinobacteria class and genera Rhodococcus,Microbacterium, Nocardia and Salinibacterium.Five representatives of these genera were selected for further studies. Theutilization of carbon sources plays an important role in species differentiation bybacteria and also by the Actinobacteria. Different strain abilities to use carbonsources (glucose, arabinose, sucrose, xylose, inositol, mannitol, fructose,rhamnose, raffinose, cellulose) were showed. More than a half of isolates werepigmented.All the strains were able to grow in a wide range of temperature (4-37 ºC) andpH (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 selectedisolates showed α-L-rhamnosidase activity under the assayed conditions.These results have given evidence of the utility of these bacteria as a source ofuseful products for biotechnology.