SELECTION OF ACTINOMYCETES STRAINS FOR BIODEGRADATION OF NAPHTHALENE, PHENANTRENE AND PYRENE

BOURGUIGNON, NATALIA; ISAAC, PAULA; AMOROSO, MARÍA J.; FERRERO, MARCELA A.

Leipzig

Congreso; 5th Congress of European Microbiologists (FEMS 2013); 2013

Federation of European Microbiological Societies

Polycyclic aromatic hydrocarbons (PAHs) are one of the major concerns because of their persistence and toxicity. Actinomycetes strains were studied for their capability of degradation of naphthalene, phenantrene or pyrene. Rhodococcus sp. 20, R. jostii, Streptomyces sp. AB0 and Streptomyces sp. A12 were isolated from contaminated soils and selectively grown on solid medium added with crystals of PAH. Removal of PAH was performed on minimal medium supplemented with 0.2 mM of each PAH and 0.1% of yeast extract. The flasks were incubated at 30 °C, 150 rpm, for 7 days. Residual PAH was extracted with acetone and determined by HPLC. Degradation of naphthalene was observed in all isolates at different rates, between 31.2 and 74.8 %. Degradation of phenantrene occurred in cultures of Streptomyces sp. AB0 (36.2 %) and Streptomyces sp. A12 (20 %), while the further degradation of pyrene was shown by Streptomyces sp. A12 (4.3 %). Because of the poor performance when growing on PAH alone, the strains were challenged to an adaptation assay that consisted in streaks successive on agar plate with PAH (0.05 mM) and decreasing concentration of glucose (from 10 to 1.25 gL-1). Then, adapted strains were cultured on MM plus PAH (phenantrene or pyrene 0.1 mM) and glucose (1.25 gL-1) as a co-substrate. An enhanced degradation of phenantrene and pyrene was observed in the presence of glucose as co-substrate of growth. These results allow us to have hope for the usefulness of these actimycetes strains in bioremediation assays of PAH in the environment.