Fu Chunqing, Jiang Yifan, Xu Bingwen, Fu Xinmei, Tan Liang, Jin Mei
School of Life Science, Liaoning Normal University, Dalian 116081, China.
Dalian Center for Certification and Food and Drug Control, Technology Innovation Center of Rapid Screening and Traceability for Edible Agricultural Product Safety, State Administration for Market Regulation, Dalian 116037, China.
Microorganisms. 2025 Mar 12;13(3):649. doi: 10.3390/microorganisms13030649.
In this study, a halotolerant bacterial strain was isolated and identified. This bacterium was confirmed to efficiently degrade s-triazine herbicides under saline conditions. The optimal conditions for the metabolism and growth of this strain were determined through single-factor tests. Furthermore, the biodegradation pathways of prometryne (the target compound) by this strain were proposed based on the detection of possible degradation intermediates and genome sequencing analysis. Additionally, a possible halotolerance mechanisms of this strain were also revealed through screening halotolerance-related genes in its genome. The results demonstrated that a halotolerant bacterial strain (designated PC), which completely degraded 20.00 mg/L prometryne within 12 h under saline conditions (30.0 g/L NaCl), was isolated and identified as . The optimal conditions for the metabolism and growth of the strain PC were identified as follows: yeast extract as the additional carbon source with the concentration of ≥0.1 g/L, NaCl concentration of ≤30.0 g/L, initial pH of 7.0, temperature of 35.0 °C, and shaking speed of ≥160 rpm. Furthermore, the strain PC demonstrated efficient removal of other s-triazine herbicides, including atrazine, ametryne, simetryne, and cyanazine. The strain PC might degrade prometryne through a series of steps, including demethylthiolation, deisopropylamination, deamination, dealkalation, decarboxylation, etc., relying on the relevant functional genes involved in the degradation of s-triazine compounds. Furthermore, the strain PC might tolerate high salinity through the excessive uptake of K into cells, intracellular accumulation of compatible solutes, and production of halophilic enzymes. This study is expected to provide a potentially effective halotolerant bacterium for purifying s-triazine pollutants in saline environments.
在本研究中，分离并鉴定了一株耐盐细菌菌株。该细菌被证实能在盐渍条件下有效降解均三嗪类除草剂。通过单因素试验确定了该菌株代谢和生长的最佳条件。此外，基于对可能的降解中间体的检测和基因组测序分析，提出了该菌株对扑灭通（目标化合物）的生物降解途径。此外，通过筛选其基因组中与耐盐性相关的基因，还揭示了该菌株可能的耐盐机制。结果表明，分离出一株耐盐细菌菌株（命名为PC），该菌株在盐渍条件（30.0 g/L NaCl）下12小时内完全降解了20.00 mg/L的扑灭通，并鉴定为 。菌株PC代谢和生长的最佳条件确定如下：酵母提取物作为额外碳源，浓度≥0.1 g/L，NaCl浓度≤30.0 g/L，初始pH值为7.0，温度为35.0 °C，振荡速度≥160 rpm。此外，菌株PC对其他均三嗪类除草剂，包括莠去津、乙嗪、西玛津和氰草津，也表现出高效去除能力。菌株PC可能通过一系列步骤降解扑灭通，包括脱甲硫基化、脱异丙基胺化、脱氨基、脱碱、脱羧等，这依赖于参与均三嗪化合物降解的相关功能基因。此外，菌株PC可能通过细胞对K的过量摄取、相容性溶质的细胞内积累以及嗜盐酶的产生来耐受高盐度。本研究有望为净化盐渍环境中的均三嗪污染物提供一种潜在有效的耐盐细菌。
