Impact of herbicide butachlor on beneficial soil bacteria

Abstract

Bioremediation is one of the most important and promising methods for elimination of butachlor as it is cheap, effective and fastest route for degradation. Bioremediation of butachlor was carried out with eight different beneficial soil bacteria. Impact of butachlor on different beneficial soil bacteria in minimal and nutrient media was studied and it showed concentration dependent effect on the bacterial growth. Effect of butachlor on soil microbial activity was examined that involved effect on bacterial population, pH, organic carbon content, available phosphorus and soil dehydrogenase activity. pH of the soil showed initial increase, followed by a decrease till the end of the experiment. Bacterial count decreased with increasing concentration of butachlor; contrastingly organic carbon content and available phosphorus were enhanced even at higher concentration throughout the experiment. Soil dehydrogenase activity was enhanced initially at lower concentrations but decreased with increase in concentration and time. GC-MS data analysis showed complete degradation of 50 ppm butachlor in 7 days by bacterial isolate DGC (Bacillus licheniformis MS514).