草甘膦降解菌A-F02的分离·鉴定及降解特性研究

目的]筛选高效草甘膦降解菌株,并研究其降解特性。方法]从草甘膦生产厂的曝气池活性污泥中分离到1株高效草甘膦降解真菌A-F02,并根据菌株形态特征和核糖体内源转录间隔区（ITS）全序列分析进行菌株鉴定。同时研究菌株对草甘膦的降解特性和影响因素。结果]经鉴定,菌株A-F02为米曲霉属。在基础盐培养基中,以草甘膦（1000mg/L）为唯一碳源,30℃、150r/min培养7d,草甘膦降解率为86.82%。通过研究添加葡萄糖量、初始pH值、温度及草甘膦浓度对米曲霉A-F02降解能力和生物量的影响结果表明,在添加葡萄糖浓度0.5%,初始pH值7.5,温度30℃,草甘膦浓度1500mg/L的条件下,菌株A-F02的生长量最大,草甘膦的降解效果最佳。结论]该研究可为草甘膦降解酶的分离纯化提供试验基础。

Isolation and Identification of Glyphosate-degrading Strain Aspergillus oryzae sp. A-F02 and Its Degradation Characteristics

Objective]The research aimed to isolate the glyphosate-degrading strain and study its degradation characteristics.Method]A glyphosate-degrading fungal strain A-F02 was isolated from sludge in an aeration tank of a glyphosate manufacture.The fungal strain A-F02 was identified by the morphological characteristics and internal transcribed spacer(ITS)region of nuclear ribosomal DNA sequence analysis.And then,the degradation characteristics of strain A-F02 to glyphosate and their influencing factors were studied.Result]The fungal strain A-F02 was identified as Aspergillus oryzae sp..The glyphosate degradation rate was 86.82% in the mineral salt medium with 1 000 mg/L of glyphosate as the sole source of carbon,after being incubated at 30 ℃ and 150 r/min for 7 d.And the biodegradation rates and biomass of the A-F02 were the highest in the culture conditions with glucose(0.5%),pH value 7.5,30 ℃ and glyphosate(1 500 mg/L).Conclusion]The research provided the experimental basis for glyphosate-degrading enzyme purification.