Volume No. 8 Issue No.: 3A Page No.: 734-740 Jan-Mar 2014




Parameswari S.* and Mekala L.

Erode Sengunthar Engineering College, Erode, Tamil Nadu (INDIA)


Received on : September 14, 2013




Currently, the pollution potential of many surface and ground waters with respect to chloropyrifos (CPF) and other toxic pesticide residues is significantly alarming and many physico-chemical treatment techniques are infeasible and/or highly uneconomical. Liquid phase biodegradation of CPF by a suitable and appropriate organism is necessary. Prior to biodegradation studies, the Actinomycetes sp. was extracted, isolated and identified through appropriate Gram staining and biochemical test (including selective media for growth of Actinomycetes sp.). The biodegradation of CPF was almost 100% at the low concentration levels between 0.5 and 2 mg/l on the other hand, for higher concentration of CPF, incomplete biodegradation could be noticed. Approximately 98.3% (around a neutral pH of 7) and beyond pH 8, complete removal could be achieved. The biodegradation kinetics was appropriately described by simple first-order kinetics with the rate constant almost doubled (between 0.04 and 0.08 1/h respective CPF concentrations of 2 and 5 mg/l). For the concentrations of CPF between 2 and 5 mg/l, the yield coefficient varied between 0.92 and 0.13 g/g, respectively, specific growth rate varied between 0.841/h and an average endogenous decay coefficient 0.016 1/h. In all the biodegradation studies pertaining to monoculture and/or mixed culture bacteria, lindane toxicity pressure was significantly noticed even after 24 h.


Keywords : Chloropyrifos, Actinomycetes, Biodegradation, Lindane, Biochemical test, Monoculture, Mixed culture