(3-Hexachlorocyclohexane ((3-HCH) is a persistent organochlorine pesticide that poses a significant threat to the ecological environment, necessitating the urgent development of effective degradation methods. Microbial degradation has demonstrated substantial potential among various bioremediation techniques due to its environmentally friendly and economical characteristics. This study evaluates the degradation capability of Enterobacter sp. CS01 on (3-HCH, its physiological responses, and its potential application in soil remediation. Under optimal conditions (pH 7, 30 degrees C), 51 % of (3-HCH was effectively removed. Metabolomics and antioxidant enzyme activity analyses revealed that CS01 defends against oxidative damage by modulating the activities of superoxide dismutase (SOD) and catalase (CAT), involving butyrate, alanine, aspartate, and glutamate metabolism, as well as the pentose phosphate pathway. CS01 converts (3-HCH into less toxic intermediates through dichloride elimination, dehalogenation of hydrogen, and hydrolysis reactions. Soil experiments indicated that soil enzyme activities (S-POD, S-DHA, S-PPO) are closely related to the degradation of (3-HCH, with the order of carbon source utilization being esters, amino acids, and sugars. This study provides new insights into the microbial degradation mechanisms of organochlorine pesticides and aids in the development of more efficient and environmentally friendly degradation technologies.

Pesticides including insecticides are applied in agricultural practices to control insect pests. However, their excessive usage often poses a severe threat to the growth, physiology, and biochemistry of plants. Here, responses of chickpea and greengram seedlings exposed to three fipronil (FIP) concentrations i. e. 100 (1x), 200 (2x) and 300 (3x) mu g mL- 1 was evaluated under in vitro. Among doses, 3x had a greater negative impact on germination attributes, root-shoot elongation, vigor indices, length ratios, and survival of seedlings. Besides, the morphological distortion in root tips, oxidative stress generation, and cellular death in fipronil-supplemented root seedlings were observed under scanning electron (SEM) and confocal laser scanning (CLSM), respectively. A significant (p <= 0.05) and pronounced upsurge in plant stressor metabolites such as proline, malondialdehyde (MDA), electrolyte leakage (EL), hydrogen peroxide (H2O2) content, and antioxidants enzymes in plant seedlings further confirmed the fipronil toxicity. In addition, a concentration-dependent decrease in respiration efficiency (RE) and ATP content in FIP-treated seedlings was observed. Reduced mitotic index (MI) and numerous chromosomal anomalies (CAs) in root meristematic cells of seedlings are a clear indication of insecticide-induced cytotoxicity. Furthermore, a dose-dependent increase in DNA damage in root meristematic cells of greengram revealed the genotoxic potential of fipronil. Conclusively, fipronil suggested phyto and cyto-genotoxic effects that emphasize their careful monitoring in soils before application and their optimum addition in soil-plant systems. It is high time to prepare both target-specific and slow-released agrochemical formulations for crop protection with concurrent safeguarding of the soil.