菌株BIT-BP004产胞外多糖影响因素及发酵液理化特性的研究

从辽河油田油水样品中分离得到一株高产胞外多糖的菌株BIT-BP004。通过对其培养条件的考察和优化,得到最适宜的培养条件为:蔗糖7.5 g/L,NaNO30.5 g/L,K2HPO41.5 g/L,KH2PO43 g/L,MgSO40.1 g/L,CaCl20.01 g/L,初始pH为6,接菌量1%。培养24 h后的胞外多糖产量为4.11 g/L。同时,通过正交实验考察了温度、矿化度和pH值对BIT-BP004发酵液理化性能的影响。结果表明,不同实验条件对发酵液黏度影响较大,影响能力大小依次为温度>矿化度>pH,其中温度是影响发酵液黏度的决定性因素。

Study on the Optimum Fermentation Condition and Physico-Chemical Property of Extracellular Polysaccharide Producing Strain BIT-BP004

An extracellular polysaccharide(EPS) producing bacteria,named BIT-BP004,was isolated from oil/water sample of Liaohe oilfield.The optimal medium compositions in shake scale for strain BIT-BP004 were determined as follows: sucrose 7.5 g/L,NaNO3 0.5 g/L,K2HPO4 1.5 g/L,KH2PO4 3 g/L,MgSO4 0.1 g/L,CaCl2 0.01 g/L,initial pH 6 and inoculant’s volume 1%.The EPS yield was 4.11 g/L in batch culture after 24 h.By orthogonal design,the factors of temperature,mineral salt concentration and pH value were selected to assay the physico-chemical property of fermentation.The results showed that experiment factors had a larger effect on viscosity of fermentation,and the affection capacity was arranged as follows,temperature > mineral salt concentration > pH,indicating that temperature was a decisive factor on the viscosity of the fermentation broth.