复合菌生物转化白酒糟发酵条件的优化

以未发酵白酒糟培养基为对照组，探讨不同菌种组合以及发酵条件对固态发酵白酒糟中蛋白含量的影响，旨在提高酒糟中真蛋白的含量。选用枯草芽孢杆菌、白地霉和产朊假丝酵母对白酒糟进行单菌和复合菌发酵实验，结果显示三菌组合发酵效果最好。通过三菌单因素发酵试验及正交试验确定最佳发酵条件为：添加15%的麸皮和2%的尿素，先接种5%的枯草芽孢杆菌和10%的白地霉30 ℃培养24 h，然后接种5%的产朊假丝酵母30 ℃培养72 h，此时真蛋白的含量为24.85%，粗蛋白含量达32.09%，粗纤维含量降低到17.66%。

Optimization of Mixed-Culture Fermentation Conditions for Biotransformation of Distilled Spirit Lees

With the aim of achieving increased true protein content of distilled spirit lees, this study investigated the effects
of different mixed cultures and solid-state fermentation conditions on protein content of distilled spirit lees. Comparison was
carried out with the unfermented control group. Fermentation experiments were conducted with pure and mixed cultures of
Bacillus subtilis, Geotrichum candidum and Candida utilis, and the best results were obtained when all the three strains were
used together. By the combined use of one-factor-at-a-time and orthogonal array design methods, the optimal fermentation
conditions were determined as follows: addition of wheat bran and urea to distilled spirit lees in proportions of 15% and 2%,
respectively, and sequential culture at 30 ℃ for 24 h with 5% Bacillus subtilis and 10% Geotrichum candidum followed
by 5% Candida utilis for 72 h. The fermented lees under these conditions contained 24.85% true protein and 32.09% crude
protein, and the crude fiber content was reduced to 17.66%.