R. Gireesh Kumar1, A. Vijaya Gopal2, R. Subhash Reddy1, CH. V. Durga Rani3, S.Triveni1 and
K. Damodara Chari1
1Department of Agricultural Microbiology and Bioenergy, College of Agriculture, Prof Jaya Shankar Telangana State Agricultural University,
Rajendranagar, Hyderabad – 500 030, India.
2Department of Agricultural Microbiology, Advanced P.G. Research Centre,
LAM, ANGRAU, Andhra Pradesh, India.
3Department of Molecular biology and Biotechnology, Institute of
Biotechnology (IBT) Prof Jaya Shankar Telangana State Agricultural
University, Rajendranagar, Hyderabad – 500 030, India.
Abstract
Sixteen bacterial isolates were obtained from insecticide treated tomato, brinjal maize and ground nut rhizospheric soils by enriching Mineral Salt Medium broth with supplement of chlorpyrifos, Phorate source. These isolates were characterized on the basis of cell morphology, cultural and biochemical properties. Among the eight chlorpyrifos degrading bacterial isolates, CDB-1isolate utilized the more pesticide. Among the eight phorate degrading bacterial isolates, the Phorate degrading bacteria (PDB)-1 isolate utilized the pesticide (Phorate) effectively. Degrading efficiency of isolates was determined by measuring the chlorpyrifos, phorate residual concentrations at intervals using Gas chromatographic method. Among the molecular diversity of 16 organophosphorus pesticide degrading isolates viz., chlorpyrifos degrading isolates 8, phorate degrading isolates 8 were also studied by PCR-RAPD technique. CDB7 shows separate lane with 26 per cent similarity compared to other isolates. CDB5 isolate shows 29 percent similar when compared with other samples. CDB3 and CDB4 reveal same genetic relatedness according to dendrogram. CDB2 and CDB6 showed 54 percent similarity and CDB1 shows 41 percent similarity. CDB3 and CDB4 isolates are more or less similar in the genome and functional properties. Whereas, CDB7 isolate was highly diverse among other isolates.. PDB5 and PDB6 showed 55 per cent similar in coefficient scale. Whereas PDB2 and PDB3 revealed 75 per cent relatedness. The other isolates, PDB1, PDB7 and PDB4 shows 64-66 percent similar. The PDB8 was highly diverse from remaining other seven isolates. PDB2 and PDB3 showed similar genome and functional properties.
Keywords: Organophosphorus degrading bacteria, minimal salt medium,
biochemical characterization, pesticide degradation ability, molecular diversity.