解淀粉芽孢杆菌GSBa-1胞外多糖的发酵制取、流变学特性和应用  

Production of Exopolysaccharide by Fermentation with Bacillus amyloliquefaciens GSBa-1,Its Rheological Characterization and Application

作　　者：赵雯[1] 腾军伟 张健[1] 赵笑[1] 姜云芸[1] 杨贞耐[1] ZHAO Wen;TENG Junwei;ZHANG Jian;ZHAO Xiao;JIANG Yunyun;YANG Zhennai(Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Laboratory of Food Quality and Safety,Beijing Technology and Business University, Beijing 100048, China)

机构地区：[1]北京食品营养与人类健康高精尖创新中心,食品质量与安全北京实验室,北京工商大学,北京100048

出　　处：《食品科学》2017年第16期1-9,共9页Food Science

基　　金：国家自然基金科学面上项目(31371804)

摘　　要：针对1株从传统酒曲中分离筛选得到的高产胞外多糖(exopolysaccharides,EPS)解淀粉芽孢杆菌GSBa-1,采用单因素试验和响应面法确定了菌株的最优产EPS发酵条件:培养基组成为胰蛋白胨10 g/L、酵母浸粉5 g/L、蔗糖40 g/L、氯化钠10 g/L;发酵温度35℃、发酵时间36 h、摇床转速160 r/min、接种量4%,在此条件下EPS产量为326.45 mg/L。对EPS的流变特性进行研究,结果表明,该EPS溶液的黏度较低,具有浓度依赖性和剪切变稠的特性,随着温度升高,黏度降低。采用激光光散射仪辅助测量EPS的分子形态:得到EPS在水溶液中重均分子质量为4.993×10~5 g/mol,回旋半径为48.34 nm,流体力学半径为64.62 nm,结构参数为0.748,该分子可能为紧密的球状结构。透射电子显微镜观察验证了EPS的球状结构。将该EPS加入到酸性乳饮料中,既不会增加其黏度,又具有良好的稳定特性,表明解淀粉芽孢杆菌GSBa-1 EPS可以作为一种新型的食品稳定剂,具有潜在的应用价值。The present study was carried out to optimize the fermentation conditions for exopolysaccharide(EPS)production by Bacillus amyloliquefaciens GSBa-1,isolated and screened from the traditional rice wine starter.The optimal fermentation conditions obtained by single factor experiments and response surface analysis were as follows:the culture medium consisted of peptone10g/L,yeast extract powder5g/L,sucrose40g/L,and NaCl10g/L and the fermentation was performed for36h at35℃with an inoculum size of4%at a shaking speed of160r/min.The maximal production of EPS of326.45mg/L was obtained under the above conditions.The results of rheological studies indicated that the aqueous solution of the EPS had low viscosity,which increased with increasing its concentration and shearing rate.Measurement of molecular parameters by multi-angle laser light scattering showed that the weight-average molecular mass(mw)of the EPS was4.993×105g/mol,the radius of gyration(Rg)48.34nm,hydrodynamic radius(Rh)64.62nm,and Rg/Rh ratio(ρ)0.748,indicating that the EPS molecule may be present as compact spheres.This was also confirmed by transmission electron microscope.The application of this EPS in acid milk beverage showed that the use of the EPS could improve the stability of the beverage without increasing its viscosity,indicating that the EPS from Bacillus amyloliquefaciens GSBa-1can be potentially used as a novel food stabilizer.

关 键 词：胞外多糖 流变特性 激光光散射 酸性乳饮料 

分 类 号：TS201.3[轻工技术与工程—食品科学]