ISSN 2736-1756
Advanced Journal of Microbiology Research Vol. 2012
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2012 International Scholars Journals
Full Length Research Paper
Isolation and characterization of a chlorpyrifos-degrading bacterium from agricultural soil and its growth response
M. Surekha Rani1, K.Vijaya Lakshmi1* P. Suvarnalatha Devi1, R. Jaya Madhuri1, S. Aruna1, K. Jyothi1, G. Narasimha2 and K.Venkateswarlu3
1Department of Applied Microbiology, Sri Padmavathi Mahila Visvavidyalayam, Tirupati – 517 502, India.
2Department of Virology, Sri Venkateswara University, Tirupati – 517 502, A.P, India.
3Department of Microbiology, Sri Krishnadevaraya University, Anantapur– 515 003, A.P, India.
Accepted 20 July, 2012
Abstract
A soil bacterium capable of utilizing chlorpyrifos as sole carbon source was isolated by selective enrichment on mineral medium containing chlorpyrifos. The bacterial isolate, designated MS09, was identified and characterized as a strain of Providencia stuartii based on biochemical characteristics and 16S rRNA sequence analysis. Growth studies showed that P. stuartii strain MS09 utilized chlorpyrifos to grow in Luria-Bertani broth containing different concentrations of chlorpyrifos at 50 -700 mg/L. However, the optimum concentration that supported bacterial growth over 24 h was found to be 50 - 200 mg/L chlorpyrifos. When compared with the control, a significant increase in bacterial growth was noted at a low concentration of chlorpyrifos (50 mg/L), whereas at higher concentrations (300 - 700 mg/L) an increased lag phase was observed, without inhibiting growth of the pesticide- utilizing bacterium. A literature survey revealed that no data is available regarding the role of P. stuartii on pesticide biodegradation.
Key words: Pesticide, chlorpyrifos, Providencia sp. (MTCC No 8099), biodegradation.