Physiological behavior of newly isolated Bacterium CB1 and Stenotrophomonas maltophilia strain CB2 on Chrysene, Pyrene, Naphthalene and Fluoranthene

Abstract

The biodegradability of some polycyclic aromatic hydrocarbons were studied in liquid culture media using bacterial strains (Bacterium CB1 and Stenotrophomonas maltophilia strain CB2) isolated from a former industrial site contaminated with organic and inorganic contaminants. The enrichment experiment was done with chrysene. The partial 16S rRNA gene analyses of Bacterium CB-1 possessed 100% similarity to an uncultured bacterium clone nbt020a while Stenotrophomonas maltophilia strain CB2 had 99% similarity to Paenibacillus sp. Y412MC10. Bacterium CB1 and Stenotrophomonas maltophilia strain CB2 degraded naphthalene between the range of 27% and 42%, chrysene 47% and 12%, fluoranthene 5% and 16%, pyrene 12% and 17% respectively. The strains utilized the test compounds as sole source of carbon and energy. As anticipated, the controls (abiotic and killed) losses were insignificant. The residual PAH obtained in some cases correlated to an increase in cell number indicating that our strains were responsible for the degradation.