一株寡营养细菌胞外多糖的摇瓶发酵研究

Study on the Conditions for Shaking Flask Fermentation of the Exopolysaccharide Production from An Oligotrophic Bacteria

摘要:

从新疆的寡营养环境——古尔班通古特沙漠中分离到一株寡营养细菌Azotobacter sp．(1～15mg碳/L培养基),通过进行Azotobacter sp．菌的单因子优化培养基的试验、摇瓶培养工艺条件的优化试验(培养温度、培养时间、初始pH值、溶氧量),确定了菌种生长与营养需求等主要因子与胞外多糖产量、粘度的关系,结果表明,摇瓶发酵的最适宜条件为:以蔗糖为碳源,碳酸钙含量为2g/L,初始pH值为7左右,种龄72～84h,磷酸二氢钾、硫酸镁的含量分别为0．3g/L、0．1g/L,接种体积分数15%,于37℃摇瓶培养72h,250mL摇瓶装液量为50mL,在适宜条件下粘多糖的产量最大可达到1145．94μg/mL,粘性可达9200 mPa·s。

Abstract:

An oligotrophic bacteria was isolated from oligotrophic environment(Gurbantunggut desert)in Xinjiang.This paper had ascer- tained the relationship between the main factors such as strain growth,nutrition demand,and the yield and viscosity of extracellular polysae- charide(EPS)by carrying on the experiment of single factor optimized culture medium(C-source.inorganic salts,etc.);the experiment of optimized conditions for shaking culture(temperature,time,the initial pH,dissolve oxygen).The optimum conditions for exopolysaccha-ride production were as follows: using sucrose as the carbon source,CaCO₃2g/L,initial pH of 7, seed age of 72-84h,KH₂PO₄0.3g/L,MgSO₄0.1g/L,inoculation quantity of 15%,cultivation 72h at 37℃,and 50 mL medium in a 250 mL flask.Under the optimal condi-tions,the yield of exopolysaccharide may reach 1145.94μg/mL,and the viscosity of fermenting liquor may reach 9200 mPa·s.