Characterization of aromatic hydrocarbon-degrading bacteria from marine sediments of Patagonia

MARCOS MS; LOZADA M; VILLALBA MS; HERRERO M; SILVA RA,; ALVAREZ HM; DIONISI HM

Mar del Plata

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Aromatic hydrocarbons are widespread pollutants in the marine environment that can represent a threat to marine life. The aim of this research was to characterize aromatic hydrocarbon degrading bacteria from marine sediments of the Patagonian coast. Using mineral media supplemented with phenanthrene and naphthalene, we isolated three halotolerant strains (PC57, PC515 and PC412), analyzed temperature and salinity growth ranges and evaluated their ability to degrade hydrocarbons. Partial 16S rRNA gene analysis showed that these strains are closely related to Bacillus subtilis QW10-11 (99.9%), Psychrobacter glacincola ANT9253 (100%) and Cobetia marina DSM4741 (100%), respectively. Using a culture-independent approach, we amplified aromatic ring-hydroxylating dioxygenase genes from sediment DNA and the PCR products were cloned and sequenced. Deduced amino acid sequences of two of the analyzed clones were most closely related to the diterpenoid dioxygenase from Pseudomonas abietaniphila BKME-9 (58% identity). Two other clones exhibited between 43 and 44% sequence identity with biphenyl dioxygenase from Rhodococcus erythropolis TA421, and six clones showed low identity values (33 to 36%) with PAH ring-hydroxylating dioxygenase from Mycobacterium vanbaalenii PYR-1. These results show the presence of diverse aromatic degrading bacteria in this coastal marine environment.