Intra species
variation among Bacillus subtilis isolated from monocrotophos contaminated agricultural
soil
Ramya N. and Maheshwar P.K.
Res. J. Biotech.; Vol. 17(1); 40-45;
doi: https://doi.org/10.25303/1701rjbt4045; (2022)
Abstract
Five (05) bacterial strains, which are capable of degrading monocrotophos, were
isolated from monocrotophos contaminated soil samples from agricultural fields of
Heggadadevana Kote, a place in Mysuru District, Karnataka, India. The ability of
the strains to degrade monocrotophos was investigated under different culture conditions.
Potential strains degrading monocrotophos was selected and named Ja- HD-1, Hom-HD-6,
Ba-HD-2, Ho-HD-2 and Ho-HD-3. The strains were identified as Bacillus subtilis on
the basis of the results of its cellular morphology, physiological, chemotaxonomic
characteristics and phylogenetic analysis of 16S ribosomal DNA (rDNA) gene sequences.
Organophosphate hydrolase (opdA gene) involved in the biodegradation of monocrotophos
in Bacillus subtilis strains was quantitatively expressed.
RT-qPCR data revealed that the strains harboring opdA gene were observed significantly
down regulating from opdA gene in a degradation stage. Growth and degradation kinetic
studies proved that the strains were able to grow in minimal salt medium containing
1000 ppm monocrotophos as the only carbon source. Hence, Ja-HD-1, Hom-HD-6, Ba-HD-
2, Ho-HD-2 and Ho-HD-3 culture strains of Bacillus subtilis have great potential
utility for the bioremediation of agriculture soils contaminated monocrotophos insecticide.
