荧光假单胞CLW17菌株对草甘膦的降解及其机制初探  

Pseudomonas fluorescens Strain CLW17:Degradation of Glyphosate and Its Mechanism

作　　者：曹永清 刘艳 张丽慧 晋婷婷[2] 任嘉红[2] CAO Yongqing;LIU Yan;ZHANG Lihui;JIN Tingting;REN Jiahong(College of Biological Sciences,Shanxi Normal University,Taiyuan 030000;Department of Biological Sciences,Changzhi College,Changzhi,Shanxi 046011)

机构地区：[1]山西师范大学生命科学学院,太原030000 [2]长治学院生命科学系,山西长治046011

出　　处：《中国农学通报》2022年第30期108-117,共10页Chinese Agricultural Science Bulletin

基　　金：国家自然科学基金“AM真菌和溶磷细菌互作对南方红豆杉生长及紫杉醇合成的效应研究”(31100471);山西省“1331工程”资助项目“太行山药用植物生物肥料工程研究中心”(1331KSC)。

摘　　要：探讨根际促生长细菌荧光假单胞菌(Pseudomonas fluorescens)CLW17对草甘膦的降解作用及其分子机制。利用平板培养法和钼锑抗比色法对CLW17菌株降解草甘膦能力进行研究。采用Plackett-Burman(PB)与Central Composite Design(CCD)试验联用确定CLW17降解草甘膦的最佳条件。对降解草甘膦关键基因thiO进行生物信息学分析,并构建敲除株(CLW17ΔthiO)及回补株(ΔthiO/thiO),研究其对草甘膦降解的影响。荧光假单胞菌CLW17菌株耐受草甘膦的最大浓度为0.7%。在降解草甘膦最优条件下,野生株CLW17、敲除株CLW17ΔthiO和回补株ΔthiO/thiO对草甘膦降解率分别为72.81%、32.78%和54.33%。生物信息学分析显示thiO基因编码366个氨基酸,拥有信号肽和跨膜结构域。CLW17具有较强的降解草甘膦能力,且thiO基因与降解草甘膦能力密切相关。研究结果可为草甘膦污染的治理及土壤修复提供良好的菌种资源。The subject is to study the degradation of glyphosate by the rhizobacteria-promoting strain Pseudomonas fluorescens CLW17 and the molecular mechanism of the strain.The glyphosate degradation ability of strain CLW17 was evaluated by plate culture method and molybdenum antimony resistance colorimetric method.An optimized condition of degrading glyphosate by strain CLW17 was achieved by employing Plackett-Burman(PB)design,and central composite design(CCD).Bioinformatics analysis was carried out for understanding the key gene thiO in glyphosate degradation.Deletion mutant strain(CLW17ΔthiO)and complement strain(ΔthiO/thiO)were constructed,and their effects on glyphosate degradation were studied.The maximum concentration of glyphosate tolerance of strain CLW17 was 0.7%.The degradation rate of CLW17,CLW17ΔthiO andΔthiO/thiO was 72.81%,32.78%and 54.33%,respectively,under the optimal condition for glyphosate degradation.Bioinformatics analysis revealed that thiO gene encoded 366 amino acids and included signal peptide and transmembrane domain.CLW17 was capable of degrading glyphosate effectively.Moreover,thiO gene was closely related to glyphosate degradation ability.These findings can provide valuable bacterial resources for glyphosate pollution control and soil remediation.

关 键 词：荧光假单胞菌 草甘膦 生物降解 优化 thiO基因 

分 类 号：Q89[生物学]