低营养细菌分泌胞外黏性物质适宜营养条件的探索

Discussion on the Appropriate Nutritional Conditions for the Extracellular Viscous Materials of an Oligotrophic Bacterium

通过对几种不同碳、氮源种类、无机盐含量和氧的需求分析,探讨其对古尔班通古特沙漠分离的一种耐低营养细菌分泌黏性物质的影响。结果表明:该菌分泌黏性物质适宜的条件,以蔗糖为碳源(15 mg C/L),无需添加任何氮源,碳酸钙含量为2 g/L、磷酸二氢钾0.3 g/L、硫酸镁0.05 g/L、氯化钠5～10 g/L,pH值为7.0。37℃摇瓶振荡培养60 h,培养液黏度可达9 000 mPa·s。与优化前培养相同时间的黏度相比提高了15%,该结果为人工合成生物结皮的一级种子生产提供了依据。

This paper discusses the effects of the several different carbon sources, nitrogen sources, inorganic salt content and oxygen on the extracellular viscous materials of an oligotrophic bacterium with the single-factor optimization method. The results show that the appropriate conditions of secreting the viscous materials from the bacterial strain are to use sucrose as the carbon source （15 mg C/L） without any N sources, CaCO3 content of 2 g/L, KH2PO4 content of 0.3 g/L, MgSO4 content of 0.05 g/L, NaCl content of 5 - 10 g/L, and pH value of 7.0. A medium of 50 mL at pH 7.0 was poured to a flask of 250 mL. After the Sterilization and inoculation, culture solution was shaken for 60 hours at 37 ℃. The viscosity of culture solution could be up to 9 000 mPa · s. The viscosity was increased by 15% under the same culture time compared with that before optimizing. Such optimization conditions can be directly used to produce the first-class germ of the artificial biotic crust.