OSMOREGULATORY ADAPTATIONS AND EFFICIENT REMOVAL OF MULTI PYRETHROID RESIDUES FROM HYPERSALINE WASTEWATER USING A HALOTOLERANT MICROBIAL ISOLATE

Sustainable and cost-efficient bioremediation of the pyrethroid pesticide industry wastewater requires the distribution of halotolerant microbial catalysts capable of maintaining metabolic activity under hypersaline conditions. In this study, a strong bacterial isolate was recovered from industrial wastewater and identified as Enterobacter ludwigii through biochemical, molecular, and phylogenetic profiling. The biodegradation kinetics of this strain were evaluated using synthetic wastewater matrices containing a consortium of five pyrethroid pesticides across a salinity gradient (1%-10% NaCl) and varying substrate loadings (50-600 mg/L). Under optimized bioprocess parameters specifically 3% NaCl and 100 ppm substrate concentration the strain exhibited superior biomass proliferation modeled by first-order kinetics and achieved biomineralization efficiency exceeding 90% within an 8-day treatment cycle. GC MS and enzymatic assays elucidated that the catabolic pathway involves a co-metabolism strategy, resulting in complete detoxification without the accumulation of toxic metabolites. Furthermore, NMR and HPLC analyses confirmed that E.ludwigii employs a specialized osmoregulatory mechanism, accumulating osmolytes to mitigate osmotic stress. These results highlight the potential of this novel E. ludwigii strain as a high-performance bio agent for the remediation of pesticide-contaminated saline environments.