微生物絮凝剂产生菌的筛选、鉴定及培养条件优化

Screening and Identification of Bioflocculant-producing Bacteria and Optimization of Their Culture Conditions

以活性污泥作为菌种来源,通过加入刚果红的寡培养基稀释涂布法和富培养基平板划线分离法,筛选出24株微生物絮凝剂产生菌,其中菌株LL6的絮凝活性最高,经鉴定,该菌为约氏不动杆菌(Acinetobacter sp.)。通过正交试验确定菌株LL6的最佳培养基成分配比为:葡萄糖,15g/L;蔗糖,10 g/L;酵母膏,0.7 g/L;尿素,0.1 g/L;硫酸铵,0.5 g/L;KH2PO4,1 g/L;K2HPO4,2.5 g/L;Mg SO4,0.3 g/L;Na Cl,0.2 g/L。通过单因子试验得出菌株LL6的最佳培养条件如下:初始p H值为6,培养温度为20℃,培养时间为24 h,摇床转速为150 r/min。

Using activated sludge as inoculum, 24 strains of bioflocculant-producing bacteria were screened by dilution coating on oligotrophic medium containing Congo red and plate streaking on eutroph- ic medium, and the flocculating activity of strain LL6 was the highest. It was identified as Acinetobacter sp. The results of orthogonal test showed that the optimum cuhure medium of strain LL6 was as follows： 15 g/L of glucose, 10 g/L of sucrose, 0.7 g/L of yeast extract, 0.1 g/L of carbamide, 0.5 g/L of am- monium sulfate, 1 g/L of KH2PO4, 2.5 g/L of K2HPO4, 0.3 g/L of MgSO4 and 0.2 g/L of NaCl. The results of single factor test showed that the optimum culture conditions of strain LL6 were as follows： ini- tial pH of 6, culture temperature of 20 ℃, culture time of 24 h and shaking speed of 150 r/min.