发酵黄酒糟中蛋白营养组分及电泳分析

Analysis of Drotein Nutritive Ingredient and Electrophoresis in Fermented Yellow-wine-lees

本试验将一株产朊假丝酵母(Candida utilis)JZ-1以及一株枯草芽孢杆菌(Bacillus subtilis)JZ-2混合后对鲜黄酒糟进行固态发酵。对发酵前后的黄酒糟进行蛋白营养成分、SDS-PAGE以及双向蛋白电泳分析,以探究发酵前后蛋白物质变化情况。结果表明,黄酒糟在发酵后有机物含量下降,粗蛋白以及多肽含量显著提高,除脯氨酸外的16种氨基酸在发酵48h后均显著增加(P<0.01)。SDS-PAGE结果表明,发酵过程中分子质量25ku以上的大分子蛋白大量降解,小分子蛋白、多肽的含量显著上升。双向蛋白电泳成功鉴定了3个表达显著上调的差异蛋白并对其进行了GO功能注释。其中,1个差异蛋白(编号2930)分子的功能为抑制丝氨酸型内肽酶活性,1个差异蛋白(编号3014)分子的功能为GTP活性以及GTP连接,还有1个差异蛋白(编号3162)分子功能未知。综上表明,在混菌固态发酵过程中,黄酒糟中相当一部分大分子蛋白被降解为小分子蛋白、多肽、氨基酸等分子量较小的降解产物,这些营养物质对于奶牛而言易于消化吸收。黄酒糟中蛋白营养质量在发酵后得到了显著提高。

Protein nutrition is crucial to animal nutrition. Two strains, including JZ-1(Candida utilis) and JZ-2(Bacillus subtilis), were used for mixed culture solid-state fermentation of fresh yellow-wine-lees. Through the analysis of protein nutrients, SDS-PAGE and two-dimensional electrophoresis on the yellow-wine-lees, the changes of protein substances between before and after 48 h-fermentation were detected. The results showed that the organic matter content decreased after fermentation, and the crude protein and peptide content increased significantly.A total of 16 amino acids except proline increased significantly after 48 h-fermentation(P<0.01). The results of SDS-PAGE showed a substantial part of large-molecule( above 25 ku) proteins were degraded after fermentation,and the content of small-molecule proteins and peptides increased significantly. From the result of the twodimensional electrophoresis, three up-regulated proteins were successfully identified. After the annotation of GO molecular functions, the molecular function of one differential protein(No. 2930) was annotated as inhibiting serine endopeptidase activity, one differential protein(No. 3014) was annotated as GTP activity and GTP binding, and the last differential protein(No. 3162)was unknown. Therefore, during the mixed culture solid-state fermentation of yellow-wine-lees, a relatively large portion of the large-molecule proteins were metabolized, and degraded into small-molecule proteins, peptides, amino acids and other nutrients. These nutrients are easy to the digest and absorb for dairy cattle. The protein nutritive quality of yellow-wine-lees is significantly improved after fermentation.