微生物絮凝剂产生菌的筛选及其培养条件优化的研究

Screening of bioflocculant-producing strains and study on optimization of their cultural conditions

采用常规的细菌分离纯化方法从土壤中分离出絮凝剂产生菌菌株,经过驯化培养后,以发酵液对高岭土混悬液的絮凝效果为指标,筛选出2株高效絮凝剂产生菌。采用单因素试验方法和正交试验设计方法,分析了影响絮凝效果的主要因素,对2个菌株的最佳培养条件进行了优化研究。结果表明:菌株S3产絮凝剂的最佳培养条件是碳源为葡萄糖(20g/L),氮源为酵母膏(2.5 g/L),培养温度为28℃,初始pH值为8,通气量为50 r/m in;菌株S21产絮凝剂的最佳培养条件是乙醇(15 g/L),氮源为复合氮源(酵母膏+脲+硫酸铵)(1.6 g/L),培养温度为28℃,初始pH值为9,通气量为200r/m in。

In this study, strains of bioflocculant-producing microorganisms were screened from soil sample by conventional methods. 2 strains with high flocculating activity were obtained after rescreening with kaolin clay suspension flocculation. Then the effects of the cultural conditions and the medium composition and proportion on bioflocculant production were studied by single factor test and orthogonal design test. The experimental results showed that the medium composition and proportion and other cultural conditions had significant effects on bioflocculant production. The optimum culture conditions of strain S3 were as follows： carbon source was glucose （20 g/L）, nitrogen source was yeast extract （2.5 g/L）, cultural temperature 28℃, initial pH 7, rotating speed 50 r/min; The optimum culture conditions of $21 were as follows, carbon source was ethanol （20 g/L） , nitrogen source was compound nitrogen source （ 1.6 g/L） , cultural temperature 28℃ , initial pH 9, rotating speed 200 r/min.