State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.
Department of Environmental Engineering and Water Technology, IHE Delft Institute for Water Education, Westvest 7, 2601DA Delft, the Netherlands.
Bioresour Technol. 2020 Nov;315:123845. doi: 10.1016/j.biortech.2020.123845. Epub 2020 Jul 15.
The main aim of this work was to study the allethrin binding interactions with esterase and its bioremediation potential using an isolated bacterial strain CW7, identified as Pseudomonas nitroreducens. The degradation conditions with strain CW7 were optimized using response surface methodology at pH 7.0, a temperature of 32 °C, and an inocula concentration of 150 mg·L, with 96% allethrin degradation observed over 7 days. The kinetic parameters q, K and K were calculated to be 0.512 day, 4.97 mg·L and 317.13 mg·L, respectively. Nine intermediate metabolites were identified after analysing the degradation products by gas chromatography-mass spectrometry. Strain CW7 effectively degraded a wide variety of pyrethroids as a carbon source. Molecular modeling, docking, and enzyme kinetics were used to investigate the binding pocket of the esterase containing amino acids such as alanine, arginine, valine, proline, cysteine, glycine, isoleucine, phenylalanine, serine, asparagine, and threonine, which play active roles in allethrin degradation.
本工作的主要目的是研究丙烯菊酯与酯酶的结合相互作用及其生物修复潜力，使用分离的细菌菌株 CW7，鉴定为假单胞菌 nitroreducens。使用响应面法在 pH 7.0、温度 32°C 和接种物浓度为 150 mg·L 的条件下优化了菌株 CW7 的降解条件，在 7 天内观察到 96%的丙烯菊酯降解。计算动力学参数 q、K 和 K 分别为 0.512 天、4.97 mg·L 和 317.13 mg·L。通过气相色谱-质谱分析降解产物，鉴定出 9 种中间代谢产物。CW7 菌株有效地降解了多种拟除虫菊酯作为碳源。使用分子建模、对接和酶动力学研究了含有丙氨酸、精氨酸、缬氨酸、脯氨酸、半胱氨酸、甘氨酸、异亮氨酸、苯丙氨酸、丝氨酸、天冬酰胺和苏氨酸等氨基酸的酯酶的结合口袋，这些氨基酸在丙烯菊酯降解中发挥着积极作用。
