微生物絮凝剂产生菌的筛选、鉴定及其培养条件的优化研究

Screening and Identification of Bioflocculant-producing Microorganism and Optimal Study on Cluture Conditions

采用常规细菌分离方法从土壤中筛选出一株高效絮凝剂产生菌,编号为B6。经过形态学特征、生理生化反应及16S rDNA序列(GenBank accession No.DQ115363)同源性比较鉴定该菌株为恶臭假单胞菌,命名为Pseudomonas putidaB6。对其培养基进行研究,确定其最佳的碳源和氮源,并通过正交试验确定其最佳的培养基成分配比(ρ/gL-1)为葡萄糖15、果糖3、KH2PO41.0、K2HPO43.0、MgSO40.1、NH4NO30.8、(NH4)2SO41.5、酵母汁0.2、NaCl0.1。同时对其培养条件进行研究,确定最佳的培养基初始pH值为8.0、培养温度为30℃、摇床速度为160r/min,以及产絮凝剂的周期变化过程。用高岭土悬浮液对其絮凝条件进行研究,确定培养液最佳的絮凝条件。

A bacterial strain named B6 which can produce bioflocculant with high flocculating activity was screened from soil by means of the common bacteria screening and purification method. The strain was identified as Pseudomonas putida B6 according to its morphological, physiological and biochemical characters, as well as 16S rDNA sequence（ GenBank accession No. DQ115363 ）homology comparison. Glucose and （NH4）2SO4 were chosen as the best carbon and nitrogen sources for bioflocculant production, and the optimum component proportion of medium（ p/gL^-1 ） which is glucose 15, fructose 3, KH2PO4 1.0, K2HPO4 3.0, MgSO4 0. 1, NH4NO3 0.8, （ NH4 ） 2SO4 1.5, yeast extra 0.2, and NaC1 0. 1, was obtained according to the orthogonal test. The optimum culture conditions are as follows ： initial pH 8.0, temperature 30℃ and agitation rate 160r/min. Its flocculant conditions were also studied with Gaoling suspension.