Gautam Pallavi, Pandey Anand Kumar, Gupta Ankush, Dubey Suresh Kumar
Molecular Ecology Laboratory, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
Department of Biotechnology Engineering, Institute of Engineering and Technology, Bundelkhand University, Jhansi, 284128, India.
Environ Pollut. 2023 May 1;324:121402. doi: 10.1016/j.envpol.2023.121402. Epub 2023 Mar 6.
Imidacloprid, a broad-spectrum insecticide, is widely used against aphids and other sucking insects. As a result, its toxic effect is becoming apparent in non-targeted organisms. In-situ bioremediation of residual insecticide from the environment utilizing efficient microbes would be helpful in reducing its load. In the present work, in-depth genomics, proteomics, bioinformatics, and metabolomics analyses were employed to reveal the potential of Sphingobacterium sp. InxBP1 for in-situ degradation of imidacloprid. The microcosm study revealed ∼79% degradation with first-order kinetics (k = 0.0726 day). Genes capable of mediating oxidative degradation of imidacloprid and subsequent decarboxylation of intermediates were identified in the bacterial genome. Proteome analysis demonstrated significant overexpression of the enzymes coded by these genes. Bioinformatic analysis revealed significant affinity and binding of the identified enzymes for their respective substrates (the degradation pathway intermediates). The nitronate monooxygenase (K7A41 01745), amidohydrolase (K7A41 03835 and K7A41 07535), FAD-dependent monooxygenase (K7A41 12,275), and ABC transporter enzymes (K7A41 05325, and K7A41 05605) were found to be effective in facilitating the transport and intracellular degradation of imidacloprid. The metabolomic study identified the pathway intermediates and validated the proposed mechanism and functional role of the identified enzymes in degradation. Thus, the present investigation provides an efficient imidacloprid degrading bacterial species as evidenced by its genetic attributes which can be utilized or further improved to develop technologies for in-situ remediation.
吡虫啉是一种广谱杀虫剂，广泛用于防治蚜虫和其他刺吸式昆虫。因此，其毒性作用在非靶标生物中日益显现。利用高效微生物对环境中的残留杀虫剂进行原位生物修复，有助于降低其负荷。在本研究中，通过深入的基因组学、蛋白质组学、生物信息学和代谢组学分析，揭示了鞘氨醇杆菌属InxBP1对吡虫啉的原位降解潜力。微观世界研究表明，吡虫啉降解率约为79%，符合一级动力学（k = 0.0726天）。在细菌基因组中鉴定出了能够介导吡虫啉氧化降解及随后中间体脱羧反应的基因。蛋白质组分析表明，这些基因编码的酶有显著的过表达。生物信息学分析显示，所鉴定的酶与其各自的底物（降解途径中间体）具有显著的亲和力和结合力。发现硝基亚铁离子单加氧酶（K7A41 01745）、酰胺水解酶（K7A41 03835和K7A41 07535）、黄素腺嘌呤二核苷酸依赖性单加氧酶（K7A41 12275）和ABC转运酶（K7A41 05325和K7A41 05605）在促进吡虫啉的转运和细胞内降解方面有效。代谢组学研究确定了途径中间体，并验证了所鉴定的酶在降解中的拟议机制和功能作用。因此，本研究提供了一种高效降解吡虫啉的细菌物种，其遗传特性证明可用于或进一步改进以开发原位修复技术。
