生物絮凝剂生产菌的分离与鉴定及其絮凝特性分析

目的]对分离自土壤样品中的一株微生物絮凝剂产生菌W5进行系统鉴定并分析其絮凝特性。方法]以细菌的16S rDNA通用引物对其基因组进行PCR扩增,并采用单因素法分析培养基的pH值、碳源和氮源对絮凝活性的影响,采用红外光谱法进行功能基团的分析。结果]同源性比对结果表明,菌株W5与Hymenobacter gelipurpurascens具有98.34%的同源性,为革兰氏阴性,长杆菌。菌株W5生长发酵培养基最佳条件为pH值7.04、葡萄糖为碳源、酵母粉为氮源。对菌株W5所产的微生物絮凝剂（MBF-W5）进行提取纯化,所得产物微红色絮状物。红外分析结果表明,MBF-W5中主要的功能基团为羟基、羧基和氨基。结论]在絮凝剂用量为150～500μl,温度为5～65℃,pH值为2～10的范围内均具有85%以上的絮凝活性。

Isolation and Identification of Bioflocculant Producing Stain and Analysis on Its Flocculating Characteristics

Objective] The aims was to indentify a bioflocculatnt producing strain W5 isolated from soil samples and analyze its flocculating characteristics.Method] The universal primers of bacterial 16S rDNA were used for PCR amplification of its genome;effects of the medium pH,carbon and nitrogen sources on its flocculating activity were analyzed by using single factor method;and infrared spectroscopy was used for functional groups analysis.Result] The results of homology comparison showed that W5 strain and Hymenobacter gelipurpurascens had homology of 98.34%,belonging to Gram-negative,long bacilli.In addition,the optimum carbon source,nitrogen source,pH value for fermentation condition were glucose,yeast extract and 7.04,respectively.Microbe flocculant produced by W5 strain(MBF-W5) was extracted and purified to obtain reddish and flocculent products.Fourier-transform infrared(FTIR) spectroscopy indicated that the major functional groups of MBF-W5 were hydroxyl,carboxyl and amino.Conclusion] Flocculating activity more than 85% was achieved under the conditions of bioflocculation dosage of 150-500 μl,temperature of 5-65 ℃ and pH 2-10.