麦秸饲料转化中木质纤维素软化技术研究

Research on softening lignocellulose technology for converting wheat straw into feed

为解决秸秆饲料转化中消化率低的问题,开发秸秆分解软化技术,优先分解部分半纤维素,以小麦秸秆为原料,以半纤维素分解为特色的分解菌复合系为接种剂,对麦秸进行高温发酵分解,通过检测秸秆木质纤维素各成分的动态、发酵参数变化,以及PCR-DGGE为手段的微生物群动态监测,研究秸秆木质纤维素结构松散的规律。结果表明,经过高温发酵,秸秆中半纤维素显著降解,9 d时半纤维素和纤维素分别分解了11.2%和9.3%;在高温发酵过程中,微生物群以细菌为主体,真菌种类较少,且细菌群中以接入的分解菌复合系的组成菌占优势。说明向高温发酵体系中添加分解菌复合系可以有效促进发酵进程,使麦秸在发酵第9 d时半纤维素的降解达到要求,有效地松散了秸秆结构。

To improve the digestibility during feed conversation of straw, this study invested a technology about degrading firstly partial hemicellulose to soften wheat straw during fermentation in vitro. Fermentation was conducted at high temperature with a starter culture of a microbial community with the high capability of degrading hemieellulose. The rule of incompact configuration of lignocellulose was detected through tracing the dynamic changes of lignoeellulose components, fermentations parameters and microbial dynamics using PCR-based Denaturing Gradient Gel Eleetrophoresis （PCR-DGGE）. The result showed that after 9 d of fermentation, the degradation of hemicellulose was significant, and the degradation ratio of hemicellulose and cellulose were 11.2% and 9.3%, respectively. The profiles of PCR-DGGE showed that the bacteria were predominant during the fermentation. The species of fungi were less. Among the bacterial species detected, those of the community were overwhelming. This showed that inoculating the microbial community into the fermentation system could significantly accelerate the fermentation process. After 9 d of fermentation, the hemicellulose was well degraded and the structure of the straw was effectively loosed.