多粘类芽孢杆菌GA1产絮凝剂的培养基和分段培养工艺

对1株从土壤中筛选的产絮凝剂微生物GA1进行了研究.该菌株经形态学特征、生理生化反应及16S rDNA序列(GenBank序列登陆号为DQ166375)相似性分析鉴定为多粘类芽孢杆菌,并命名为Paenibacillus polymyxa GA1.对其进行了产絮凝剂培养条件和培养工艺的研究.结果表明:GA1产絮凝剂的最佳培养基成分(g/L)为蔗糖40.0、酵母浸膏4.0、K₂HPO₄5.0、KH₂PO₄、2.0、NaCl 0.1、MgSO₄ 0.2.研究了该菌株产絮凝剂的最佳培养条件,包括培养基的初始pH、培养温度、摇床速度和接种量.同时针对其产絮凝剂和菌体生长的关系,首次将分段培养工艺应用于GA1产絮凝剂中,即在培养的初期24h内采用菌体生长最佳培养条件,在培养后期采用菌体产絮凝剂的最佳培养条件.结果表明,采用分段培养的工艺,既可保证GA1絮凝剂的产量,又能缩短培养周期.

Culture Medium and Grading Culture Technics for Bioflocculant Production by Paenibacillus polymyxa GA1

A bacterial strain named GA1 which can produce bioflocculant with high flocculating activity was isolated from soil.The strain was identified as Paenibacillus polymyxa according to its morphological,physiological and biochemical characters,as well as 16S rDNA sequence(GenBank Accession number: DQ166375) similarity comparison.The results indicated that sucrose and yeast extract were the optimal carbon and nitrogen sources for bioflocculant production.Furthermore, the mass ratio of sucrose to yeast extract and the optimal sucrose concentration were ascertained.The optimum component proportion of medium((g/L)) is sucrose(40.0,) yeast extract 4.0,K₂HPO₄ 5.0,KH₂PO₄ 2.0,NaCl 0.1,MgSO₄ 0.2.The culture conditions including initial pH,temperature,agitation rate and inoculation quantity of strain GA1 were ascertained.Based on the relation of bacterium growth and bioflocculant production,grading culture was applied to bioflocculant production of GA1.The experimental result show that grading culture can keep high bioflocculant yield as well as shorten time of flocculant production.