氯嘧磺隆降解真菌的分离和鉴定

Isolation and identification of a chlorimuron-ethyl degrading fungi

从田间多年施用氯嘧磺隆的土壤中，驯化分离得到1株能够以氯嘧磺隆为唯一碳源和能源生长的真菌，命名为F31。该菌株在麦芽汁平板培养基上形成的菌落为乳白色，奶油状、表面光滑；经电镜观察，细胞长卵形，长5～7μm，宽3～4．5μm。糖类发酵试验表明，该菌株能发酵葡萄糖、蔗糖、麦芽糖、半乳糖，不能发酵淀粉、乳糖；同化碳源试验表明，该菌株能利用葡萄糖、蔗糖、麦芽糖、乙酸钠，不能利用淀粉；同化氮源试验表明，该菌株不能利用硝酸钾，能利用硫酸铵、尿素。根据其形态特征、生理生化特性、18SrRNA序列分析，初步鉴定F31为酿酒酵母（Saccharomyces cerevisiae），

A fungi strain, coded as F31 which could utilize chlorimuron-ethyl as sole carbon and energy source for growth, was isolated and screened from the soil of long term applied with chlorimuron-ethyl. The fungi colonies on Mayazhi plate appeared milk white in color, ereamily, mierospheres smoothed. F31 was long ovate, 5-7μm in length and 3-4.5μm in breadth. The saceharide fermentation tests showed that the strain could ferment glucose, sucrose, maltose and galactose, could not ferment amylum and lactose. The carbon source assimilation tests showed that the strain could utilize glucose, sucrose, maltose and sodium acetate, could not utilize amylum. The nitrogen source assimilation tests showed that the strain could not utilize potassium nitrate, could utilize ammonium sulphate and urea. Based on its morphological, physiological and biochemical properties as well as the 18S rRNA sequence analysis results, the strain was tentatively identified as Saccharomyces cerevisiae.