啤酒糟中细菌的分离鉴定及其在啤酒糟发酵中的应用

该研究采用传统培养分离法从啤酒糟中分离细菌，通过形态观察及分子生物学技术对其进行菌种鉴定，选择其中3株细菌发酵啤酒糟，并与常规发酵真菌黑曲霉（Aspergillus niger）和出芽短梗霉（Aureobasidium pullulans）对比，以期获得对啤酒糟降解效果较好的细菌。结果表明，从啤酒糟中共分离得到6株细菌（编号为B1～B6），经鉴定，分别为蜡样芽孢杆菌（Bacillus cereus）、梭状菌属（Clostridium sp.）、解淀粉芽孢杆菌（Bacillus amyloliquefaciens）、贝莱斯芽孢杆菌（Bacillus velezensis）、暹罗芽孢杆菌（Bacillus siamensis）、枯草芽孢杆菌（Bacillus subtilis）。其中解淀粉芽孢杆菌B3对啤酒糟的降解效果最好，且优于常规真菌，其发酵啤酒糟的蛋白质、总还原糖、阿魏酰低聚糖含量、木聚糖酶酶活、羧甲基纤维素酶酶活均最高，分别为25.26%、3.92%、10.01 μmol/L、803.59 U及38.16 U。

Isolation and identification of bacteria from brewer's spent grain and their application in the fermentation of brewer's spent grain

In this study, bacteria were isolated from brewer's spent grain by traditional culture isolation method, and identified by morphological observation and molecular biology techniques. 3 strains of bacteria were selected and used in the fermentation of brewer's spent grain and compared with the conventional fermentation fungi of Aspergillus niger and Aureobasidium pullulans, so as to obtain the bacteria with better degradation effect on brewer's spent grain. The results showed that a total of 6 strains of bacteria (B1-B6) were isolated from brewer's spent grain and identified as Bacillus cereus, Clostridium sp., Bacillus amyloliquefaciens, Bacillus velezensis, Bacillus siamensis, and Bacillus subtilis. Among them, B. amyloliquefaciens B3 had the optimal degradation effect on brewer's spent grain, and was better than conventional fungi. The contents of protein, total reducing sugar, feruloyl oligosaccharide, xylanase activity and carboxymethyl cellulase activity of the fermented brewer's spent grain were all the highest, which were 25.26%, 3.92%, 10.01 μmol/L, 803.59 U and 38.16 U, respectively.