微生物絮凝剂产生菌NX-2的筛选和合成条件的研究

从土壤中筛选分离到 1株高效絮凝剂产生菌NX 2 ,鉴定为枯草芽孢杆菌 (Bacillussub tilis)。在含谷氨酸和葡萄糖的培养基中培养 ,其发酵产物粘度高 ,对高岭土、活性炭等固体悬浮颗粒具有显著的絮凝作用 ,而缺少谷氨酸和额外碳源则不能产生絮凝活性。NX 2培养并产生絮凝活性的碳源可采用葡萄糖、蔗糖、麦芽糖、甘油、可溶性淀粉和果糖 ,氮源采用酵母膏、蛋白胨等有机氮源或铵盐等无机氮源。通过核磁共振等手段对分离提纯的样品进行结构表征 ,鉴定其为γ 聚谷氨酸。

The Screening of a Flocculant-producing Bacterium NX-2 and Its Characteristics

A flocculant producing bacterium strain NX 2 was screened and identified to Bacillus subtilis A medium containing glutamic acid was indispensable to the production of flocculant by NX 2 The highly flocculating activity in kaolin and active carbon suspension was obtained using glucose and yeast extract as carbon and nitrogen sources Ammonium salts was a suitable and economical nitrogen source The flocculating activity was released mostly in the supernatant of culture broth The flocculant purified from supernatant using ethanol precipitation was determined to be poly γ glutamic acid using amino acid analyzer and NMR