一株新的a-淀粉酶抑制剂生产菌株ZG0656及其产物的发酵、分离、性质与应用

A Novel Strain ZG0656 Producing a-Amylase Inhibitor and Fermentation, Separation, Properties, and Application of Its Products

摘要:

从土壤中分离并筛选得到了一株a-淀粉酶抑制剂生产菌, 编号ZG0656。根据形态特征、培养特征、生理生化特征、细胞壁化学组成特征和16S rDNA全序列相似性比较分析等多相分类方法, 确认菌株ZG0656为天蓝黄链霉菌的新变种, 命名为天蓝黄链霉菌南开变种(Streptomyces coelicoflavus var. nankaiensis)。该菌经10 L发酵罐水平发酵, 发酵液中可积累一定量的a-淀粉酶抑制剂。采用浓缩, 树脂吸附, 凝胶过滤, 减压干燥等方法得到a-淀粉酶抑制剂混合物。该a-淀粉酶抑制剂为含氮的拟低聚糖类物质, 能强烈抑制哺乳动物来源的a-淀粉酶, 对餐后高血糖的形成有明显改善作用, 可用于制备治疗糖尿病、肥胖症的药物或功能性食品。

Abstract:

A strain ZG0656 producing α-amylase inhibitor was isolated from soil in this study. Polyphasic taxonomic studies were performed, including appearance characteristics, culture characteristics, phenotypic characteristics, cell walls chemical composition, nearly complete 16S rDNA sequence alignment with those of representative Streptomyces species. These results revealed that strain ZG0656 represents a novel variation of Streptomyces coelicoflavus, for which we propose the name S. coelicoflavus var. nankaiensis. After fermentation in a 10 L fermentor, a-amylase inhibitors were accumulated in the harvested broth of strain ZG0656. The a-amylase inhibitors we obtained were identified as aminooligosaccharides after concentration, resin-adsorption, gel-filtration, and desiccation. They could intensively inhibit α-amylase, depress postprandial blood glucose elevation obviously. Thus, the α-amylase inhibitors are expected to act as drugs or functional food against diabetes.