锰氧化细菌与生物锰氧化物聚集体完全降解磺胺甲恶唑的分子机制研究

The extensive use of antibiotics in animal feeding has caused excessive veterinary antibiotic residues in the environment and result in far-reaching consequences for the environmental ecosystem. The manganese-oxidizing Pseudomonas. sp. MY62 that could be degraded of sulfamethoxazole was isolated from livestock and poultry wastewater in the previous period. In this project, a Pseudomonas. sp. MY62 as starting strain, the aggregate constituting by manganese-oxidizing bacteria and manganese oxide formed in the process of oxidation of Mn(II) will be used as degradation material, jointly utilizing the chemical oxidation of manganese oxide, biological degradation activity of bacterial and oxidation of free radicals generated during Mn(II) oxidation, the aggregate will be used to degrade the sulfamethoxazole. Using the stable isotope tracer technique, the degradation pathway of sulfamethoxazole by the aggregates will be preliminarily elucidated. Using transcriptome analysis and other molecular biological means, the important Sulfamethoxazole degradation relate redox proteins in Pseudomonas. sp. MY62 will be identified. By the addition of enzyme inhibitors and chemical blockers, the specific reactions catalyzed by enzymes, manganese oxides and free radicals will be analyzed, and the molecular mechanism of degradation of sulfamethoxazole by Pseudomonas. sp. MY62 and aggregates will be revealed. This project will systematically study the degradation of sulfamethoxazole by aggregate, and resolve the molecular mechanism of the degradation of sulfamethoxazole by aggregate. This project is of great significance to enrich the remediation methods of hard-to-degrade antibiotics pollution in the environment, open up new technologies for harmless treatment of livestock and poultry wastes, and promote cross convergence of biological and chemical methods in the treatment of environmental pollution.

畜禽饲养过程中抗生素的大量使用造成环境中抗生素残留超标，对环境生态系统有长远的危害。申请人前期从畜禽废水中分离得到的一株锰氧化假单胞菌MY62，可以降解磺胺甲恶唑。本项目拟以MY62在氧化Mn(II)过程中与锰氧化物形成的聚集体为降解材料，联合利用锰氧化细菌的生物氧化作用和锰氧化物的化学氧化作用及自由基的强氧化作用降解磺胺甲恶唑；利用稳定性同位素示踪技术，阐明磺胺甲恶唑的完全降解途径；利用转录组测序分析和基因中断等分子生物学手段，鉴定锰氧化假单胞菌MY62中与磺胺甲恶唑降解相关的氧化还原蛋白；通过添加酶抑制剂和化学阻断剂分析酶和氧化锰及自由基催化的具体反应，揭示假单胞菌MY62和聚集体降解磺胺甲恶唑的分子机制。本项目系统研究聚集体对磺胺甲恶唑的降解作用，对丰富环境中的难降解抗生素污染的修复方法，开发畜禽废弃物无害化处理新技术，促进生物和化学方法在治理环境污染中的交叉融合具有重要意义。

畜禽饲养过程中抗生素的大量使用造成环境中大量的兽用抗生素残留。抗生素残留对环境生态系统有深远的危害。本项目利用从磺胺类抗生素污染的畜禽废水中分离得到的一株锰氧化假单胞菌MY62，以MY62在氧化Mn2+过程中与锰氧化物形成的聚集体为降解材料，联合利用锰氧化细菌的生物氧化作用和锰氧化物的化学氧化作用及自由基的强氧化作用降解磺胺甲恶唑。项目通过稳定性同位素示踪技术，检测到聚集体降解磺胺甲恶唑的关键中间产物6种和终产物CO2的存在，得到生物锰氧化物聚集体对磺胺甲噁唑先物理吸附在进行逐步降解的动力学曲线，确认生物锰氧化物聚集体对磺胺甲噁唑的完全降解作用和降解条件。通过转录组分析确定锰氧化假单胞菌MY62中降解磺胺甲噁唑的关键降解蛋白3个，初步确认生物氧化和自由基氧化在生物聚集体完全降解磺胺甲恶唑过程中的作用。发现了生物锰氧化物的广谱性污染物降解作用。本项目对丰富抗生素污染修复的方法，治理环境中的抗生素污染残留，促进生物和化学方法在治理环境污染中的交叉融合具有重要意义。