1株海洋来源鞘氨醇单胞菌胞外多糖的含量测定

Determination of extracellular polysaccharides produced by marine derived Sphingomonas sp. WG

目的建立1种简便快捷的测定海洋来源鞘氨醇单胞菌分泌的胞外多糖威兰胶含量的方法。方法通过测定威兰胶同葡萄糖的换算因子以及发酵液中葡萄糖和总糖的浓度,建立了1种利用苯酚-硫酸法测定发酵液中威兰胶含量的方法,并采用单因素及正交实验对该方法的影响因素进行了优化及方法学验证。结果最佳的优化条件为:苯酚用量为0.8mL、浓硫酸用量为6mL、显色时间为30min、显色温度为80℃。方法学验证结果表明,该方法的平均回收率为98.94%,相对标准偏差(RSD)为0.53%;显色产物在2h内稳定,RSD为0.48%;仪器的精密度良好,RSD为0.77%。结论建立的苯酚-硫酸法可用于发酵液中威兰胶的含量测定。

Objective To establish a simple and rapid method for determination of the concentration of welan gum,extracellular polysaccharide produced by marine derived bacterium Sphingomonas sp.WG.Methods A phenol-sulfuric acid colorimetry method was developed to calculate the production of welan gum by the estimation of the conversion factor of welan gum to glucose,the concentration of residual glucose and total sugars in fermentation broth.Furthermore,the influence factors of the methods were optimized by single factor and orthogonal experiment,and validation of the method was carried out.Results The optimum determination conditions were 0.8 mL phenol,6 mL sulfuric acid,80 ℃ for 30 min.The results showed that the average recovery rate was up to 98.94%,the RSD was 0.53%.The chromogenic product could keep stable within 2hand RSD was 0.48%.In addition,the precision of the instrument was good,RSD was 0.77%.Conclusion The developed phenol sulfuric acid method could be used for quantitative determination of welan gum in fermentation broth.