草甘膦降解菌分离与鉴定.docVIP

草甘膦高效降解菌的筛选鉴定 张艳明 （安徽农业大学植物保护学院，安徽合肥 230036） 摘 要：草甘膦是目前世界上广泛使用的一种有机磷除草剂，长期大量使用所造成的环境污染已不容忽视．微生物降解是生物修复草甘膦污染土壤的有效途径之一．本实验通过富集分离方法，从受草甘膦污染的土壤中以草甘膦为唯一碳、氮源进行筛选，共分离得到11株对草甘膦具有降解能力的真菌菌株。利用分光光度法对菌株降解能力进行测定，发现NCY-5菌株在草甘膦浓度为1.2 g·L-1的培养基中，摇床培养7天后降解率高达83.63%，具有较高的研究及应用价值。通过显微形态特征观察，初步断定菌株NCY-5属于瓶霉属真菌。 关键词：草甘膦；农药残留；降解；分离筛选 Isolation and identification of a highly efficient glyphosate degrading strain ZHANG Yan-ming , CHEN Long , ZHAO Bin ,ZHANG Han-ping (Department of Plant Protection,Anhui Agricultural University,Hefei Anhui 230036) Abstract: Glyphosate is commonly used as an organophosphate herbicide in the world. But continuously using the herbicide will cause environmental pollution seriously. Biodegradation is an effective way of bioremedying the polluted soil. In order to degrade glyposate eleven glyphosate degradable strains were obtained from glyphosate contaminated soil by using screening and separation cultural medium method which used glyphosateas the unique carbon and nitrogen source. The degradation rate of glyphosate of the strains was detected by using spectrophotometry method. One of the strains showed potential for further research and utilization with a 83.63% degradation rate which incubating for 7 days in the culture medium with glyphosate concentration by 1.2g·L-1. Based on physiological of the microscope, the strain NCY-5 was identified as Phialophora. Key words: Glyphosate; Pesticide residue; Degradation; Isolation 草甘膦（Glyphosate）是一种高效、低毒、低残留的广谱灭生性有机磷农药[1]，适用于农田、林木和果园等地[2]，其作用机理是抑制5-烯醇式丙酮酸草酸-3-磷酸合成酶（EPSP合成酶）的活性，阻断芳香族氨基酸的生物合成[3-5]，从而使杂草死亡。在过去几十年中,草甘膦农药的开发与应用,曾为人类在农、林业生产中防治病害、提高农作物产量中起到了不可磨灭的积极作用。近年来，随着草甘膦的长期、大量施用，相继出现了一些问题，如杂草抗性、防除效果降低、对非靶标生物和生态环境造成的污染破坏等，草甘膦使用之后的环境效应及其修复技术逐渐引起科学工作者的关注[6-9] 目前自然环境中存在的部分细菌、真菌、放线菌、藻类等对有机磷农药具有降解作用，研究得比较深入的有细菌和真菌2类。细菌包括：假单孢菌属(Pseudomonas) 、芽孢杆菌属 (Bacillus) 、节细菌属(Arthrobacter) 、棒状杆菌属(Corynebacterium ) 、黄杆菌属(Flavobacterium) 、黄单孢杆菌属(Xanthomonas)等。真菌主要有:曲霉属(Aspergillus) 、青霉属(Penicillium) 、木霉属(Trichoderma) 、镰刀菌属(Fusarium)等[10-12]