A microcosm study on bioremediation of fenitrothion-contaminated soil using Burkholderia sp.. FDS-1

Fenitrothion, a toxic organophosphorus pesticide, can build up the concentration of nitrophenolic compound in soils and hence needs to be removed. Burkholderia sp. FDS-1, a fenitrothion-degrading strain, was used in this work to study factors affecting its growth, and then evaluated for its capacity to degrade fenitrothion in soil microcosms. Minimal salt medium containing 1% (w/v) glucose was found to be a suitable carbon source for inoculum preparation. Various factors, including soil pH, temperature, initial fenitrothion concentration, and inoculum size influenced the degradation of fenitrothion. Microcosm studies performed with varying concentrations (1-200 mg kg(-1)) of fenitrothion-spiked soils showed that strain FDS-1 could effectively degrade fenitrothion in the range of 1-50 mg kg(-1) soil. The addition of Burkholderia sp. FDS-1 at 2 x 10(6) colony forming units g(-1) soil was found to be suitable for fenitrothion degradation over a temperature range of 20-40 degrees C and at a slight alkaline pH (7.5). The results indicate that strain FDS-1 has potential for use in bioremediation of fenitrothion and its metabolite-contaminated sites. This is a model study that could be used for decontamination of sites contaminated with other compounds. (c) 2006 Elsevier Ltd. All rights reserved.