Department of Agricultural Biotechnology, Faculty of Agriculture, Assam Agricultural University, 785013, Jorhat, Assam, India.
DBT-North East Centre for Agricultural Biotechnology, Assam Agricultural University, 785013, Jorhat, Assam, India.
World J Microbiol Biotechnol. 2022 Dec 27;39(2):59. doi: 10.1007/s11274-022-03507-x.
Long-term use of toxic pesticides in agricultural grounds has led to adverse effects on the environment and human health. Microbe-mediated biodegradation of pollutants is considered an effective strategy for the removal of contaminants in agricultural and environmental sustainability. Imidacloprid, a neonicotinoid class of pesticides, was widely applied insecticide in the control of pests in agricultural fields including the tea gardens of Assam. Here, native bacteria from imidacloprid contaminating tea garden soils were isolated and screened for imidacloprid degradation efficiency under laboratory conditions. Out of the 30 bacterial isolates, 4 were found to tolerate high concentrations of imidacloprid (25,000 ppm), one of which isolate MBSB-12 showed the highest efficiency for imidacloprid tolerance and utilization as the sole carbon source. Morphological, biochemical, and 16 S ribosomal RNA gene sequencing-based characterization revealed the isolate as Pseudomonas plecoglossicida MBSB-12. The isolate reduced 87% of extractable imidacloprid from the treated soil in 90 days compared to the control soil (without bacterial treatment). High-Resolution Mass Spectrometry (HRMS) analysis indicated imidacloprid breakdown to comparatively less harmful products viz., imidacloprid guanidine olefin [m/z = 209.0510 (M + H)], imidacloprid urea [m/z = 212.0502 (M + H)] and a dechlorinated degraded product of imidacloprid with m/z value 175.0900 (M + H). Further investigation on the molecular machinery of P. plecoglossicida MBSB-12 involved in the degradation of imidacloprid is expected to provide a better understanding of the degradation pathway.
长期在农业用地中使用有毒农药会对环境和人类健康产生不良影响。微生物介导的污染物生物降解被认为是去除农业和环境可持续性中污染物的有效策略。吡虫啉是一种新烟碱类杀虫剂，被广泛应用于控制包括阿萨姆茶园在内的农业领域的害虫。在这里，从受吡虫啉污染的茶园土壤中分离出了土著细菌，并在实验室条件下筛选了它们对吡虫啉的降解效率。在 30 个细菌分离物中，有 4 个被发现能够耐受高浓度的吡虫啉（25,000 ppm），其中一个分离物 MBSB-12 显示出最高的吡虫啉耐受和利用效率，可作为唯一的碳源。形态学、生化和 16S 核糖体 RNA 基因测序特征表明，该分离物为恶臭假单胞菌 MBSB-12。与对照土壤（无细菌处理）相比，该分离物在 90 天内将处理土壤中可提取的 87%的吡虫啉降解。高分辨率质谱（HRMS）分析表明，吡虫啉分解为相对较少的有害产物，即吡虫啉胍烯烃 [m/z=209.0510（M+H）]、吡虫啉脲 [m/z=212.0502（M+H）] 和脱氯降解产物吡虫啉，其 m/z 值为 175.0900（M+H）。进一步研究恶臭假单胞菌 MBSB-12 降解吡虫啉的分子机制有望更好地了解其降解途径。
