Chai Ran, Guo Jiaxiang, Yang Chuanzhong, Zhu Dan, Li Tao, Yang Wen, Liu Xinxin, Chen Xing, Huang Shuai, Wang Haifeng, Yao Xinding, Gao Yuqian, Qiu Liyou
Yellow River Conservancy Technical Institute, Kaifeng, 475004, China.
College of Life Sciences, Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture and Rural Affairs, Henan Agricultural University, Zhengzhou, 450046, China.
Sci Rep. 2025 Apr 24;15(1):14296. doi: 10.1038/s41598-025-97273-z.
In this study, a novel nonylphenol (NP)-degrading bacterium, Pseudoxanthomonas mexicana CH, was isolated from wastewater treatment plant effluent. Phylogenetic analysis showed its close relationship to P. mexicana AMX 26BT. The strain displayed chemotaxis toward NP, with Mcp24 as the key chemoreceptor. The Mcp24 deletion mutant (CH- 1) had weaker chemotaxis and NP degradation (over 30% lower in solution and 8% lower in sludge than the wild type). In vitro, Mcp15's C-terminal pentapeptide DWQEF was methylated by CheR. Using CRISPR, this pentapeptide was added to Mcp24 to create CH- 2. CH- 2 showed better NP chemotaxis (17% higher in plate assays and 39% higher in capillary assays) and higher NP degradation rates (23.5% and 24.2% higher in solution and sludge, respectively). These findings demonstrate that NP acts as a bacterial chemoattractant, with Mcp24 as the receptor. Enhancing Mcp24's C-terminal pentapeptide improves chemotaxis and degradation efficiency, representing a significant advancement in bioremediation by strengthening bacterial responses to pollutants.
在本研究中，从污水处理厂的流出物中分离出一种新型的壬基酚（NP）降解细菌——墨西哥假黄单胞菌CH。系统发育分析表明，它与墨西哥假黄单胞菌AMX 26BT关系密切。该菌株对NP表现出趋化性，以Mcp24作为关键化学感受器。Mcp24缺失突变体（CH-1）的趋化性和NP降解能力较弱（在溶液中比野生型低30%以上，在污泥中低8%）。在体外，Mcp15的C末端五肽DWQEF被CheR甲基化。利用CRISPR技术，将该五肽添加到Mcp24中，构建出CH-2。CH-2表现出更好的NP趋化性（平板试验中高17%，毛细管试验中高39%）和更高的NP降解率（在溶液和污泥中分别高23.5%和24.2%）。这些发现表明，NP作为一种细菌化学引诱剂，以Mcp24作为受体。增强Mcp24的C末端五肽可改善趋化性和降解效率，这代表了通过增强细菌对污染物的反应在生物修复方面取得的重大进展。
