产胞外多糖菌的鉴定及多糖性质研究

Identification of an exopolysaccharide-producing bacteria and study on properties of polysaccharide

从华南农业大学杀虫植物园土壤中筛选出一株胞外多糖高产菌株PS04,根据形态学、生理生化特征以及16SrD-NA核酸序列分析结果表明,该菌属于多粘类芽孢杆菌。采用察氏培养基,pH 6.0,于37℃摇瓶培养48h,多糖产量为13.3g/L。对其多糖性质研究表明,该多糖的性质与黄原胶类似,具有低浓度下高黏性、假塑性、耐盐性,同时对热及酸碱有较好的稳定性。

Strain PS04 producing exopolysaccharide was isolated from the soil samples that were collected from the South China Agricultural University Botanic Insecticides Garden.It was identified as a Paenibacillus polymyxa by its morphological,the physiological and biochemical properties and 16S rDNA sequence analysis.Using Czapek＇s medium,the exopolysaccharide production was up to 13.3 g/L by fermentation under the condition of temperature 37 ℃ and pH 6.0.The properties of the polysaccharide were investigated.Like Xanthan Gum,this polysaccharide was distinguished by its high viscosity with low concentration,pseudoplasticity and salt-tolerance,at the same time,the polysaccharide was stable to heating,acid and alkali.