在体外模拟瘤胃发酵条件下N-乙酰-DL-蛋氨酸稳定性的研究

通过两个试验,研究在体外模拟瘤胃发酵条件下N-乙酰-DL-蛋氨酸的降解率。试验1:N-乙酰-DL-蛋氨酸在pH值6.5、温度为39℃的缓冲液中孵育9h,其降解率为3.3%。试验2:运用瘤胃体外发酵技术研究N-乙酰-DL-蛋氨酸不同添加量对pH值、氨态氮、微生物蛋白动态变化的影响。结果表明,添加0.4、0.6gN-乙酰-DL-蛋氨酸发酵3～6h,均能够显著降低体系的pH值;添加0.6gN-乙酰-DL-蛋氨酸发酵12h能够显著提高氨态氮的浓度;N-乙酰-DL-蛋氨酸在发酵过程中不影响微生物蛋白产量。以上结果显示,N-乙酰-DL-蛋氨酸在体外模拟瘤胃发酵的条件下可以稳定存在。

Study of the stability of N-Acetyl-DL-Methionine in vitro simulating rumen fermentation system

Two experiments are conducted in this paper to study the degradation rates of N-Acetyl-DL-Methionine in vitro simulating rumen fermentation system.In Exp.1,under the conditions of pH 6.5 and 39 ℃,the degradation rate is about 3.3% after 9 hours of culture.In Exp.2,the kinetic effects of gradient doses of N-Acetyl-DL-Methionine were carried out on pH value and concentrations of ammonia nitrogen and microbial protein.The results indicated:that pH value is reduced significantly by the dosage of 0.4 and 0.6 g respectively after adding 3～6 hours;that the concentrations of ammonia nitrogen is increased significantly by the dosage of 0.6 g after fermenting 12 hours.During the fermentation,the microbial protein was not affected.It is inferred that N-Acetyl-DL-Methionine is stable under the condition of in vitro simulating rumen fermentation system.