Biodegradation of 1,1-diphenylethylene and 1,1-diphenylethane by Pseudomonas putida PaW 736

In the present study, the possibility of biodegrading the dechlorinated product of 1,1,1-trichloro-2,2-bis(4chlorophenyl)ethane (DDT), 1,1-dichloro-2,2-bis(chlorophenyl)ethylene (DDE) and structurally related compound 1,1-dichloro-2,2-bis(chlorophenyl)-ethane (DDD) under aerobic conditions was examined. Since commercial preparation of 1,1-diphenylethane was not available, a structurally related compound, 1,1-diphenylethylene was chosen for the acclimatization of bacterial culture. More than 95% of 1,1-diphenylethylene (initial concentration 500 mg l⁻¹) was degraded by naphthalene degrading Pseudomonas putida PaW 736 within six days. GS-MS analysis revealed the formation of benzophenone as the end-product with residual concentration of 157 mg l⁻¹ after six days of incubation. 1,1-diphenylethane was formed from the complete dechlorination of DDT using Mg°/Pd⁺⁴ bimetallic system. P. putida PaW 736 acclimated to 1,1-diphenylethylene was also able to degrade 1,1-diphenylethane (initial concentration 250 mg l⁻¹) using it as the sole source of carbon and energy. More than 80% degradation of 1,1-diphenylethane was observed following 5 days of incubation. However, any metabolites of the biodegradative pathway for the degradation of 1,1diphenylethane could not be identified.