Fermentation is considered as one of the most useful biological modification techniques to increase the bioactivity of polysaccharides. In this study, Saccharomyces cerevisiae and Bacillus subtilis were used to ferment wheat bran, and the effects of the fermentation on the structural characteristics and antioxidant activity of wheat bran polysaccharides were investigated. Two polysaccharides were isolated from unfermented and fermented wheat bran and labelled as wheat bran polysaccharides-1 (WBP-1) and fermented wheat bran polysaccharides-1 (FWBP-1), respectively. The results showed fermentation increased the content of total polysaccharides, enhanced the proportions of rhamnose, xylose and arabinose and improved the proportion of fucose to a detectable level. After fermentation, the molecular weight of FWBP-1 (21.19 kDa) was lower than that of WBP-1 (52.02 kDa). In vitro, FWBP-1 exhibited higher reducing power and stronger 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical scavenging activities. In zebrafish model, FWBP-1 also displayed superior protective effects against 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced reactive oxygen species (ROS) production, lipid peroxidation, and cell death. Taken together, S. cerevisiae and B. subtilis fermentation could change the structural characteristics and enhance the antioxidant activity of polysaccharides from wheat bran.

发酵被认为是增加多糖生物活性的最有用的生物修饰技术之一。在这项研究中，酿酒酵母和枯草芽孢杆菌用麦麸发酵，研究了发酵对麦麸多糖结构特征和抗氧化活性的影响。从未发酵和发酵的麦麸中分离出两种多糖，分别标记为麦麸多糖-1（WBP-1）和麦麸多糖-1（FWBP-1）。结果表明，发酵增加了总多糖的含量，增加了鼠李糖，木糖和阿拉伯糖的比例，并将岩藻糖的比例提高到可检测的水平。发酵后，FWBP-1（21.19 kDa）的分子量低于WBP-1（52.02 kDa）的分子量。体外，FWBP-1表现出更高的还原能力和更强的1,1-二苯基-2-吡啶并肼基（DPPH）清除自由基和羟自由基的活性。在斑马鱼模型中，FWBP-1还显示出对2,2'-偶氮二（2-甲基丙ion）二盐酸盐（AAPH）诱导的活性氧（ROS）产生，脂质过氧化和细胞死亡的优异保护作用。两者合计，酿酒酵母和枯草芽孢杆菌的发酵可能改变结构特性和增强从麦麸多糖的抗氧化活性。