期刊名称：Journal of Environmental and Occupational Science
印刷版ISSN：2146-8311
出版年度：2015
卷号：4
期号：1
页码：44-52
DOI：10.5455/jeos.20141214124733
出版社：International Medical Journal Management and Indexing System
摘要：Aim: The present study has been designed to compare two commonly used methods viz. microbial and enzymatic for the degradation of monocrotophos (MCP) in sandy loam soil of Rajasthan. Methods: Methodology involves the use of molecularly characterized fungal strain Aspergillus niger JQ660373. For the microbial method spore suspension (1 × 108 spores/ml) was used as inoculum. Enzymatic method employ the use isolated, purified extracellular fungal hydrolases as inoculum. %age of MCP degradation was assessed in the form of residual MCP concentration and hence degradation kinetics was calculated. The results were confirmed by using analytical tools, high pressure thin layer chromatography (HPTLC) and Fourier transform infrared spectroscopy (FTIR). Results: The results of this study demonstrated that extracellular fungal hydrolase composed of two different subunits of 33 and 67 Kd. Both subunits synergistically degrade MCP. Residual MCP concentration was found to be 64.94 ± 0.42 and 16.95 ± 0.55 µg mlâ1 after 15 days of incubation for microbial and enzymatic method, respectively. Degradation of MCP followed first order kinetics with rate constants of 0.002 and 0.136 dayâ1 and hence the calculated half-life was found to be 12.64 and 5.14 days, respectively. HPTLC chromatograms clearly indicate the significant decrease in the standard MCP peak (rf 0.19-0.21) with increasing incubation duration. Molecular insight of MCP degradation was studied by FTIR. Degradation proceeded with hydrolytic cleavage of MCP resulting in the formation of inorganic phosphates (âPO4). Conclusion: The study concludes that enzymatic method of degradation was more efficient than the microbial method.
