Li Lizhi, Qu Mingren, Liu Chanjuan, Xu Lanjiao, Pan Ke, Song Xiaozhen, OuYang Kehui, Li Yanjiao, Zhao Xianghui
Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, China.
Front Microbiol. 2018 Nov 30;9:2944. doi: 10.3389/fmicb.2018.02944. eCollection 2018.
Agricultural straws, such as rice straw, wheat straw, and corn straw, are produced abundantly every year but not utilized efficiently in China. An experiment was conducted to determine the effects of recombinant xylanase on ruminal fermentation and microbial community structure in incubation of these straws. The recombinant xylanase from (rLeXyn11A) was produced in . The optimal temperature and pH for rLeXyn11A were 40°C and 4.0, respectively. The rLeXyn11A featured resistance to high temperature and showed broad temperature adaptability (>50% of the maximum activity at 20-80°C). Supplemental rLeXyn11A enhanced the hydrolysis of three agricultural straws. After ruminal incubation, regardless of agricultural straws, the fiber digestibility, acetate concentration, total volatile fatty acids (VFAs) production, and fermentation liquid microbial protein were increased by rLeXyn11A. Supplemental rLeXyn11A increased the ammonia-N concentration for corn straw and rice straw. High throughput sequencing and real-time PCR data showed that the effects of rLeXyn11A on ruminal microbial community depended on the fermentation substrates. With rice straw, rLeXyn11A increased the relative abundance of fibrolytic bacteria including Firmicutes, , Ruminococcaceae and its some genus, and . With wheat straw, rLeXyn11A increased the relative abundance of and its three representative species . With corn straw, the fibrolytic bacteria Firmicutes, , and were increased by rLeXyn11A. This study demonstrates that rLeXyn11A could enhance ruminal digestion and fermentation of agricultural straws, showing the potential of rLeXyn11A for improving the utilization of agricultural straws in ruminants.
农业秸秆，如稻草、小麦秸秆和玉米秸秆，在中国每年产量丰富，但未得到有效利用。进行了一项实验，以确定重组木聚糖酶对这些秸秆体外培养时瘤胃发酵和微生物群落结构的影响。来自[具体来源]的重组木聚糖酶（rLeXyn11A）在[具体表达系统]中产生。rLeXyn11A的最佳温度和pH分别为40°C和4.0。rLeXyn11A具有耐高温特性，且温度适应性广（在20 - 80°C时活性>最大活性的50%）。补充rLeXyn11A可增强三种农业秸秆的水解。瘤胃体外培养后，无论何种农业秸秆，rLeXyn11A均可提高纤维消化率、乙酸盐浓度、总挥发性脂肪酸（VFA）产量和发酵液微生物蛋白。补充rLeXyn11A可提高玉米秸秆和稻草的氨氮浓度。高通量测序和实时PCR数据表明，rLeXyn11A对瘤胃微生物群落的影响取决于发酵底物。对于稻草，rLeXyn11A增加了包括厚壁菌门、[未提及的菌属]、瘤胃球菌科及其一些属以及[未提及的菌属]在内的纤维分解菌的相对丰度。对于小麦秸秆，rLeXyn11A增加了[未提及的菌属]及其三个代表性物种的相对丰度。对于玉米秸秆，rLeXyn11A增加了厚壁菌门、[未提及的菌属]和[未提及的菌属]等纤维分解菌。本研究表明，rLeXyn11A可增强农业秸秆的瘤胃消化和发酵，显示出rLeXyn11A在提高反刍动物农业秸秆利用率方面的潜力。
