MOLECULAR INSIGHTS INTO PESTICIDE TOLERANCE: PROTEIN INDUCTION AND DNA DAMAGE IN ORGANOPHOSPHATE-DEGRADING BACTERIA

Abstract

One of the effects of the intensified agricultural activities involves environmental pollution by pesticides, which are bound to get into the soil and ultimately into the water sources through leaching. The recurrent exposure of soil microbiota to these poisonous substances facilitates the process of adaptive resistance and catabolic functions. In the current research, bacterial cultures taken in Karuppur and Salem pesticide-contaminated agricultural soils were filtered on their capability to decompose organophosphate pesticides. Two strong isolates, which were referred to as Bacillus sp. and Micrococcus sp. had a great level of tolerance and degradation capacity. Significant biomolecular changes in these isolates were observed after long-term exposure (three months) to organophosphate pesticides. A protein estimation showed a strong rise in the overall total protein content indicating the activation of stress-related and degradative enzymes. Genomic DNA damage was identified by DNA ladder assay, which is a genotoxic stress caused by pesticides. Thus, plasmid profiling also revealed a rise of copy number and change of the size of plasmids, implying potential adaption through plasmids and greater degradation potential. This evidence indicates that long-term exposure to pesticides leads to microbial adaptation in terms of physiological and genetic changes to allow survival in adverse environments. The isolates identified have great potential to be used in bioremediation strategies that will be used in detoxifying the soils that have been contaminated with organophosphate.