College of Food Science, Shenyang Agricultural University, Shenyang, 110866, People's Republic of China.
Foreign Language Teaching Department, Shenyang Agricultural University, Shenyang, 110866, People's Republic of China.
Glycoconj J. 2020 Jun;37(3):307-317. doi: 10.1007/s10719-020-09923-1. Epub 2020 Apr 15.
The aim of this study was to characterize the exopolysaccharide (EPS) produced by Bacillus velezensis SN-1 (B. velezensis SN-1) (EPS-SN-1), which was isolated from the fermented Da jiang. The microbe made crude exopolysaccharides EPS-SN-1 was produced throughout the bacterial growth period, and the highest yield (2.7 g/L) was obtained with sucrose as the carbon source. As per high performance liquid chromatography (HPLC), EPS-SN-1 is a heteropolysaccharide consisting of glucose, mannose and fructose, with a high molecular weight of 2.21 × 10 Da. FTIR spectra further indicated the presence of hydroxyl and carbonyl groups, and NMR analysis confirmed both α- and β-glycosidic bonds. Furthermore, differential scanning calorimetry (DSC) showed that EPS-SN-1 has high thermal stability with fusion point of 270.7 °C. Finally, EPS-SN-1 demonstrated strong antioxidant capacity via its ability to scavenge hydroxyl radical (OH), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, ABTS radical (ABTS) and oxygen radical (O). Taken together, EPS-SN-1 is a promising natural antioxidant and probiotic with potential applications in the food industry.
本研究旨在对从发酵大酱中分离得到的解淀粉芽孢杆菌 SN-1（Bacillus velezensis SN-1）所产生的胞外多糖（EPS）进行表征。该微生物在整个细菌生长期间产生粗胞外多糖 EPS-SN-1，当以蔗糖作为碳源时，产量最高（2.7 g/L）。根据高效液相色谱（HPLC）分析，EPS-SN-1 是一种由葡萄糖、甘露糖和果糖组成的杂多糖，分子量高达 2.21 × 10 Da。傅里叶变换红外光谱（FTIR）进一步表明存在羟基和羰基，核磁共振（NMR）分析证实了 α-和 β-糖苷键的存在。此外，差示扫描量热法（DSC）表明 EPS-SN-1 具有较高的热稳定性，熔融点为 270.7°C。最后，EPS-SN-1 通过清除羟基自由基（OH）、1,1-二苯基-2-苦基肼基（DPPH）自由基、ABTS 自由基（ABTS）和氧自由基（O）表现出较强的抗氧化能力。综上所述，EPS-SN-1 是一种有前途的天然抗氧化剂和益生菌，具有在食品工业中的潜在应用价值。
