Some Factors Affecting Degradation of Organochlorine Pesticides by Bacteria

Open Access
Publisher Website
Google Scholar
Abstract
Whole cells of Bacillus cereus, Bacillus coagulans, Bacillus subtilis, Escherichia colt and Enterobacter aerogenes in trypti- case soy broth degraded DDT into two to eight metabolites. Seven metabolites were from aerobic growth of the Bacillus. Simi- lar metabolites were from anaerobic growth of E. colt and E. aerogenes but less than four metabolites were from aerobic growth of thes~ organisms. Metabolic pathway for the degradation of DDT was similar for the aforementioned species: DDT > DDD ) DDMU > DDMS ) DDNU ) (DDOH) ~ DDA ) DBP or DDT ) DDE. Whole cells of Pseudomonas fluorescens and Staphylo- coccus aureus were unable to degrade DDT under aerobic conditions. None of the species was eapable of de- grading DDT in skimmilk or in trypticase soy broth containing 3% whole casein. Deg- radation was greatly reduced in trypticase soy broth containing 4.5% lactose or indi- vidual fractions of a-, fl- and y-easein. None of the species degraded dieldrin and heptachlor. diehloro-2,2-bis (p-chlorophenyl) ethane) and smaller amounts of DDE (),l-diehloro-2,2-bis (p-