抗草甘膦酵母菌ZM-1的分离鉴定及其生长降解特性

Isolation and Identification of a Glyphosate-resistant Yeasty Strain (ZM-1) and Its Optimal Growth and Degradation Traits

摘要:

以福州市郊区的耕作土壤为研究材料, 利用草甘膦为选择压力, 通过富集、驯化培养, 分离出一株对草甘膦具有高耐受和降解作用的酵母菌菌株ZM-1, 结合生理生化特征及26S rDNA D1/D2区序列分析将其初步鉴定为胶红酵母菌(Rhodotorula mucilaginosa)。菌株ZM-1能以草甘膦为唯一碳、氮源生长, 对草甘膦的最高耐受浓度为50 g/L。在草甘膦初始浓度为1 g/L的无机盐培养基中, 30°C、150 r/min 摇床振荡培养7 d, 草甘膦降解率为85.38%。适合菌株ZM-1生长及降解草甘膦的最佳条件为: 草甘膦初始浓度1 g/L, 接种量4%, 温度30°C, pH 值5.5-6.0, 装料量50 mL/250 mL。菌株ZM-1是一株良好的草甘膦耐受菌, 可用于草甘膦污染环境的生物修复, 也可能成为转基因抗草甘膦作物的一个很好资源。

Abstract:

Using glyphosate as the sole selective pressure, a yeast strain ZM-1 was isolated by enrichment-domestication culture technique from cultivated soils in the suburb around Fuzhou, PR China. The strain was identified as Rhodotorula mucilaginosa based on its physiological, biochemical and 26S rDNA D1/D2 domain sequences analysis. Strain ZM-1 grew with glyphosate as sole carbon and nitrogen source. The maximum glyphosate tolerant concentration for ZM-1 was 50 g/L. Strain ZM-1 was cultivated for 7 d under the conditions that glyphosate concentration 1 g/L, temperature 30°C, and rotation speed 150 r/min with 85.38% glyphosate-degraded rate. With the basal salts medium, the optimal conditions for growth and glyphosate-degraded rate for the strain were as follow: initial glyphosate concentration 1 g/L, inoculating dose 4% (V/V), temperature 30°C, pH value 5.5-6.0 and medium contents 50 mL/250 mL, respectively. Strain ZM-1 could play an important role in bioremediation of glyphosate-contaminated environment, and may be a potential resource in the study of glyphosate-resistant GMO plant.