一株粘性多糖产生菌LV-1的发酵条件研究

Research on the Fermentation Conditions of a Viscous Polysaccharide-producing Bacterium LV-1

[目的]研究从土壤中分离到的粘多糖生产菌LV-1的发酵条件。[方法]以梯度稀释法筛选粘多糖产生菌,探讨碳源、氮源、初始pH值和温度对粘多糖生产的影响,确定最佳发酵条件。[结果]对LV-1菌株粘性多糖产物的理化性质分析发现,该多糖易溶于水,难溶于乙醇、正丁醇、氯仿等有机溶剂,为中性多糖,pH值7.5,带负电荷,不含蛋白质、果糖基、糖醛酸基和硫酸根,无还原末端,不具有淀粉样结构。LV-1菌株的最佳发酵条件为:3%甘露醇为碳源,0.25%酵母粉为氮源,培养基初始pH值7.0,培养温度28℃。[结论]该研究可为LV-1菌的开发利用及粘性多糖的工业化生产提供依据。

[Objective] The fermentation conditions of a viscous polysaccharide-producing bacterium LV-1 which isolated from soil sample were studied.[Method] The polysaccharide-producing bacterium was isolated by serial dilution method,the effects of carbon source,nitrogen source,the initial pH and temperature on producing polysaccharide by it were discussed to confirm the optimum fermentation conditions.[Result] The physicochemical properties showed that the polysaccharide was water-soluble,but insoluble in organicolvents including ethanol, butanol, and chloroform. It was neutral polysaccharide with negative charge and witbout reducing terminal. The pH of its solution was pH 7.5. There were no protein, fructose, uronic acid, sulphate and starch-like structure included in polysaccharide molecules. The optimum fermentation conditions for polysaccharide production were 3% mannitol as carbon source, 0.25% yeast extract as nitrogen source, culture temperature 28 ℃ and pH 7.5. [Conclusion] The reseaw3a could provide basis for development and utilization of LV-I and industrialized production of viscous polysaccharide.