Yu Lan, Wang Yingning, Shan Xiaoqing, Ma Fang, Guo Haijuan
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, China.
Microorganisms. 2022 Mar 18;10(3):648. doi: 10.3390/microorganisms10030648.
Sulfamethoxazole (SMX) is a widespread and persistent pollutant in the environment. Although the screening and analysis of SMX-degrading bacteria have been documented, the interaction mechanisms of functional microorganisms are still poorly understood. This study constructed a consortium with strain YL1 and YL2 supplied with SMX as the sole carbon and energy source. The coexisting mechanism and the removal of SMX of the consortium were investigated. The total oxidizable carbon (TOC) removal rate of the combined bacterial system was 38.94% compared to 29.45% for the single bacterial system at the same biomass. The mixed bacterial consortium was able to resist SMX at concentrations up to 400 mg/L and maintained a stable microbial structure at different culture conditions. The optimum conditions found for SMX degradation were 30 °C, pH 7.0, a shaking speed of 160 r·min, and an initial SMX concentration of 200 mg·L. The degradation of SMX was accelerated by the addition of YL2 for its ability to metabolize the key intermediate, 4-aminophenol. The removal rate of 4-aminophenol by strain YL2 reached 19.54% after 5 days. Genome analysis revealed that adding riboflavin and enhancing the reducing capacity might contribute to the degradation of SMX. These results indicated that it is important for the bioremediation of antibiotic-contaminated aquatic systems to understand the metabolism of bacterial communities.
磺胺甲恶唑（SMX）是环境中一种广泛存在且持久的污染物。尽管已有关于筛选和分析降解SMX细菌的文献报道，但功能微生物的相互作用机制仍知之甚少。本研究构建了一个以YL1和YL2菌株组成的菌群，以SMX作为唯一碳源和能源。研究了该菌群的共存机制及对SMX的去除情况。在相同生物量下，混合细菌系统的总可氧化碳（TOC）去除率为38.94%，而单一细菌系统为29.45%。该混合细菌菌群能够耐受高达400 mg/L的SMX，并在不同培养条件下保持稳定的微生物结构。发现SMX降解的最佳条件为30℃、pH 7.0、振荡速度160 r·min以及初始SMX浓度200 mg·L。由于YL2能够代谢关键中间体4-氨基苯酚，添加YL2可加速SMX的降解。5天后，菌株YL2对4-氨基苯酚的去除率达到19.54%。基因组分析表明，添加核黄素和增强还原能力可能有助于SMX的降解。这些结果表明，了解细菌群落的代谢对于抗生素污染水体系统的生物修复至关重要。
