从贵阳市郊区玉米地根际土样中分离筛选得到一株产胞外多糖的细菌GY04菌株，其16S rDNA同源性分析表明该菌株为放射形土壤杆菌(Agrobacterium radiobacter)。采用均匀设计原理对GY04菌株产胞外多糖的发酵工艺进行优化，利用统计软件SPSS(V 10.0)分析，得到GY04菌株产胞外多糖的最佳发酵工艺条件：牛肉膏2.000 g/L，乙二醇2.775 g/L，碳酸钙2.000 g/L，初始pH值7.000，接种量7.000%。在此发酵工艺条件下，多糖产量达(2.683±0.6

A bacterium strain, GY04, was isolated from sand soil of a maize field in suburb of Guiyang. The analysis of DNA sequence suggests that the strain of GY04 is Agrobacterium radiobacter. With the principle of the uniform design, the fermentation conditions of the strain GY04 are optimized. Analyzing by SPSS(V10.0), the optimal fermentation process is determined. They are beef extract 2.000g/L, glycol 2.775 g/L, calcium carbonate 2.000g/L, the initial pH7.000, the inoculum amount 7.000%. On these conditions, the production of the saccharide can be achieved the most, about (2.683±0.600) g/L. The results also show that bacterium A. radiobacter possess good waterretention ability as a microbial waterretaining agent.

国家重点基础研究发展计划973项目(2006CB403200);国家自然科学基金资助项目(40463001)