一株产结冷胶的少动鞘氨醇单胞菌的筛选鉴定

Screening and Identification of Sphingomonas paucimobilis Producing Gellan Gum

为了获得利用蔗糖高产结冷胶的野生菌株,从北海涠洲岛表层土样分离筛选出一株利用蔗糖高产结冷胶的野生菌株,命名为gxas-815。经Biolog生理生化分析和16S r DNA序列分析,鉴定该菌为少动鞘氨醇单胞菌(Sphingomonas paucimobilis)。此菌株能以蔗糖为原料发酵生产结冷胶,摇瓶实验表明,在含3%蔗糖、0.3%蛋白胨、0.15%磷酸氢二钾、0.15%硫酸钾、0.25%磷酸二氢钾、0.3%无水硫酸镁的发酵培养基中的结冷胶产量达13.75 g/L,结冷胶每克蔗糖产率达0.458 g,并且能利用糖蜜中除蔗糖外的其他碳源。

In order to obtain wild strain producing gellan gum from sucrose, a strain producing gellan gum was screened out from top soil of Weizhou island in Beihai city and identified as Sphingomonas paucimobilis by physiological-biochemical testing and 16S rDNA gene sequence homology analysis. The optimal medium for gellan gum production was obtained with the composition of （%）： sucrose 3%, tryptone 0.3%, K2HPO4, K2SO4 0.15%, KH2PO4 0.25%, MgSO4 0.3%. The production of gellan gum from sucrose was 13.75 g/L. The yield of sucrose was 0.458 g per gram, it could ferment others carbon source of molasses besides sucrose.