中文摘要：

【目的】研究特定氨基酸在人工瘤胃体外培养条件下如何影响瘤胃微生物群系特征及其发酵。【方法】研究中以3只瘘管山羊作为瘤胃液供体,采用底物去除技术,底物设计分别为：全量必需氨基酸组（TEAA）,组氨酸、赖氨酸、蛋氨酸和支链氨基酸（BCAA）的缺省组。【结果】底物对培养液pH均值没有显著性影响,但各组pH值随时间的变化模式有所不同;培养液氨氮浓度较高,在10.99～30.51mg/100ml范围变动,各组氨氮浓度随时间的变化模式也有明显的不同;特定氨基酸缺省对微生物蛋白产量限制程度不同,以BCAA缺省对微生物蛋白产量的限制最大,相对于全量组混合微生物蛋白下降了44.52%。研究还发现底物对微生物区系也有一定的影响,原虫与细菌比值以赖氨酸缺省组最低（89.12%）,BCAA缺省组最高（127.60%）（P〈0.01）。另外,微生物的PCR-SSCP图谱显示微生物区系内的种属也因底物变化而发生了改变。【结论】底物氨基酸对瘤胃混合微生物群系及其发酵有一定的影响作用,支链氨基酸是瘤胃混合微生物生长所必需的氨基酸。

英文摘要：

[ Objective ] Expeniments were conducted to investigate how mmen microbes and fermentation change with certain amino acids in vitro. [ Method]Three goats fitted with cannula were used to provide mmen liquor. The removal method was applied. Treatments of total essential amino acid （TEAA）, His-removal, Lys-removal, Met-removal, and branch chain amino acids （BCAA）-removal were designed. [Result] The substrates showed no significant influence on the average pH value, but each had a different pattern with time change. The recorded concentration of NH3-N ranged between 10.99 to 30.51 mg/100 ml, while observed to be much higher in incubation medium varied patterns with time change. Yields of microbial protein varied with treatments, with lowest decrease of 44.52% in the treatment with BCAA-removal （P〈0.01） compared to the group of TEAA. As for micro-flora, the protozoa to bacteria ratio was lowest for treatment group with Lys-removal （89.12%）, while highest for the group with BCAA-removal （127.60%） （P〈0.01）. Furthermore, PCR-SSCP analysis revealed microbial profile change within bacteria or protozoa group subjected to the substrates. [Conclusion] Dietary amino acid influences both fermentation and microbial community. Branch chain AAs are essential AA for the growth of mminal mixed microbes.