Diversity of culturable sodium dodecyl sulfate (SDS) degrading bacteria isolated from detergent contaminated ponds situated in Varanasi city, India

In the present investigation, an attempt has been made to isolate and identify SDS-degrading bacteria from different detergent contaminated ponds situated in Varanasi city, UP, India. Initial survey of ponds indicated that these ponds were contaminated with detergents. Employing enrichment technique in minimal medium (PBM) with SDS as a sole carbon source, a total of 24 isolates were recovered from 7 detergent contaminated ponds. Studies on rates of SDS degradation indicated that the rate of SDS degradation varied from 97.2% to 19.6% after 12h incubation under identical conditions. An estimation of alkyl sulfatase activity indicated that the activity varied from 0.168 +/- 0.004 to 0.024 +/- 0.005 mu mol SDS/mg protein/min. Molecular characterization of these isolates was performed on the basis of ARDRA and ERIC PCR, which indicated that these isolates were broadly divided in 8 groups. Some selected isolates were identified on the basis of 165 rDNA sequencing. It was found that these isolates belonged to Pseudomonas aeruginosa, Pseudomonas mendocina, Pseudomonas stutzeri, Pseudomonas alcaligenes, Pseudomonas pseudoalcaligenes, Pseudomonas putida and Pseudomonas otitidis respectively. Among these isolates P. aeruginosa, P. putida and P. otitidis have been previously shown to degrade and metabolize SDS, the rest of the isolates appear to be new. (C) 2011 Elsevier Ltd. All rights reserved.