Abstract：
Glyphosate is a broad spectrum and non-selective herbicide employed to control different weeds in agricultural and urban zones and to facilitate the harvest of various crops. Currently, glyphosate-based formulations are the most employed herbicides in agriculture worldwide. Extensive use of glyphosate has been related to environmental pollution events and adverse effects on non-target organisms, including humans. Reducing the presence of glyphosate in the environment and its potential adverse effects requires the development of remediation and treatment alternatives. Bioremediation with microorganisms has been proposed as a feasible alternative for treating glyphosate pollution. The present study reports the glyphosate resistance profile and degradation capacity of the bacterial strain Burkholderia cenocepacia CEIB S5-2, isolated from an agricultural field in Morelos-México. According to the agar plates and the liquid media inhibition assays, the bacterial strain can resist glyphosate exposure at high concentrations, 2000 mg·L-1. In the degradation assays, the bacterial strain was capable of fast degrading glyphosate (50 mg·L-1) and the primary degradation metabolite aminomethylphosphonic acid (AMPA) in just eight hours. The analysis of the genomic data of B. cenocepacia CEIB S5-2 revealed the presence of genes that encode enzymes implicated in glyphosate biodegradation through the two metabolic pathways reported, sarcosine and AMPA. This investigation provides novel information about the potential of species of the genus Burkholderia in the degradation of the herbicide glyphosate and its main degradation metabolite (AMPA). Furthermore, the analysis of genomic information allowed us to propose for the first time a metabolic route related to the degradation of glyphosate in this bacterial group. According to the findings of this study, B. cenocepacia CEIB S5-2 displays a great glyphosate biodegradation capability and has the potential to be implemented in glyphosate bioremediation approaches.
摘要：
草甘膦是一种广谱的非选择性除草剂，用于控制农业和城市地区的不同杂草并促进各种作物的收获。目前,基于草甘膦的制剂是全世界农业中使用最多的除草剂。草甘膦的广泛使用与环境污染事件和对非目标生物的不利影响有关，包括人类。减少草甘膦在环境中的存在及其潜在的不利影响需要开发补救和治疗替代方案。已经提出用微生物进行生物修复作为处理草甘膦污染的可行替代方案。本研究报告了从莫雷洛斯州的一个农田中分离出的伯克霍尔德氏菌CEIBS5-2菌株的草甘膦抗性概况和降解能力。根据琼脂平板和液体培养基抑制试验，细菌菌株可以抵抗高浓度的草甘膦暴露，2000mg·L-1。在降解试验中，该菌株能够在短短8小时内快速降解草甘膦（50mg·L-1）和主要降解代谢产物氨甲基膦酸（AMPA）。B.cenocapiaCEIBS5-2基因组数据的分析揭示了编码酶的基因的存在，涉及草甘膦生物降解通过两种代谢途径报道，肌氨酸和AMPA。这项研究提供了有关伯克霍尔德氏菌属物种在除草剂草甘膦及其主要降解代谢物（AMPA）降解中的潜力的新信息。此外，对基因组信息的分析使我们首次提出了与该细菌组中草甘膦降解相关的代谢途径。根据这项研究的结果,B.cenocepaciaCEIBS5-2显示出巨大的草甘膦生物降解能力，并有可能在草甘膦生物修复方法中实施。
