Guangxi Key Laboratory for Agro-Environment and Agric-Products Safety, National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning, Guangxi, 530004, People's Republic of China.
Guangxi Key Laboratory for Agro-Environment and Agric-Products Safety, National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning, Guangxi, 530004, People's Republic of China.
Chemosphere. 2023 Apr;319:137980. doi: 10.1016/j.chemosphere.2023.137980. Epub 2023 Jan 27.
Agrobacterium rhizogenes AT13, a novel bacterial strain that was isolated from contaminated soil, could utilize atrazine as the sole nitrogen, thereby degrading it. Optimization of the degradation reaction using a Box-Behnken design resulted in 99.94% atrazine degradation at pH 8.57, with an inoculum size of 3.10 × 10 CFU/mL and a concentration of 50 mg/L atrazine. Ultra-high performance liquid chromatography-electrospray ionization-high resolution mass spectrometry (UPLC-ESI-HRMS), liquid chromatography tandem mass spectrometry (LC-MS/MS) and high performance liquid chromatography (HPLC) analyses identified and quantified six reported metabolites and a novel metabolite (2-hydroxypropazine) from atrazine degradation by AT13. On the basis of these metabolites, we propose an atrazine degradation pathway that includes dichlorination, hydroxylation, deamination, dealkylation and methylation reactions. The toxicity of the degradation products was evaluated by Toxicity Estimation Software Tool (T.E.S.T). Bioaugmentation of atrazine-polluted soils/water with strain AT13 significantly improved the atrazine removal rate. Thus, AT13 has potential applications in bioremediation.
发根农杆菌 AT13 是从污染土壤中分离得到的一种新型细菌菌株，它可以利用莠去津作为唯一的氮源，从而对其进行降解。采用 Box-Behnken 设计对降解反应进行优化，结果表明，在 pH 值为 8.57、接种量为 3.10×10 CFU/mL、莠去津浓度为 50mg/L 的条件下，莠去津的降解率达到了 99.94%。超高效液相色谱-电喷雾电离-高分辨质谱联用（UPLC-ESI-HRMS）、液相色谱串联质谱（LC-MS/MS）和高效液相色谱（HPLC）分析鉴定并定量了 AT13 降解莠去津产生的 6 种已知代谢物和 1 种新代谢物（2-羟基丙嗪）。基于这些代谢物，我们提出了莠去津的降解途径，包括二氯代、羟化、脱氨、脱烷基和甲基化反应。利用毒性评估软件工具（T.E.S.T.）对降解产物的毒性进行了评估。用菌株 AT13 对莠去津污染的土壤/水进行生物强化，显著提高了莠去津的去除率。因此，AT13 在生物修复中具有潜在的应用价值。
