Kanamarlapudi Sri Lakshmi Ramya Krishna, Muddada Sudhamani
Department of Biotechnology, KL University, Green Fields, Vaddeswaram, Guntur 522502, India.
Biomed Res Int. 2017;2017:4201809. doi: 10.1155/2017/4201809. Epub 2017 Jul 26.
An exopolysaccharide (EPS) producing strain CC30 was isolated from raw milk and identified as with morphological and 16S sequencing analysis. The strain was shown to produce 1.95 g/L of EPS when grown in skim milk lactose medium at 30°C by increasing the viscosity of the medium. The EPS was isolated and purified, and it was shown to consist of glucose and galactose in 1 : 1 ratio, with molecular weights ranging from 58 to 180 kDa. FTIR spectroscopy indicated the EPS to have amide, hydroxyl, and carboxyl groups. Under Atomic Force Microscopy, EPS showed spike-like lumps of EPS. Scanning Electron Microscopy (SEM) studies showed that it had irregular lumps with a coarse surface. The EPS displayed pseudoplastic nature. Thermogravimetric analysis (TGA) reported a degradation temperature of 110.84°C. The purified EPS exhibited reducing activity, hydrogen peroxide radical scavenging activity, and emulsification activity. The results of the present study indicated that EPS producing could serve as a promising candidate for further exploitation in food industry.
从生牛奶中分离出一株产胞外多糖（EPS）的菌株CC30，并通过形态学和16S测序分析对其进行了鉴定。当该菌株在30°C的脱脂牛奶乳糖培养基中生长时，通过增加培养基的粘度，显示其能产生1.95 g/L的EPS。EPS被分离和纯化，结果表明它由葡萄糖和半乳糖以1∶1的比例组成，分子量范围为58至180 kDa。傅里叶变换红外光谱（FTIR）表明EPS含有酰胺基、羟基和羧基。在原子力显微镜下，EPS呈现出穗状块状物。扫描电子显微镜（SEM）研究表明，它具有表面粗糙的不规则块状物。EPS表现出假塑性特性。热重分析（TGA）报告其降解温度为110.84°C。纯化后的EPS表现出还原活性、过氧化氢自由基清除活性和乳化活性。本研究结果表明，产EPS的菌株有望在食品工业中得到进一步开发利用。
