奶牛瘤胃需氧及兼性厌氧菌的PCR-16S rDNA鉴定及日粮的影响

PCR-16S rDNA Identification of Aerobe and Facultative Anaerobe from Rumen of Cows and Affected by the Dietary

设计9个精料梯度的日粮饲喂干乳期成年荷斯坦奶牛,并对其瘤胃液中的部分细菌进行了分离,PCR-16SrDNA鉴定和动态检测。结果显示,以瘤胃液为原料,采用人工培养基共分离到56株细菌,并对7株具代表性的细菌进行了PCR扩增,经序列同源性比较,最终把细菌鉴定为牛链球菌(A0625、A1212、0131)、蜡样芽孢杆菌(0113)、地衣芽孢杆菌(0091)、短小芽孢杆菌(0083)和嗜热链球菌(0123)。同时还发现随精料浓度的增加,牛链球菌、芽孢杆菌及嗜热链球菌的数量均呈不同程度的上升趋势。结果表明不同精料浓度的日粮对奶牛瘤胃需氧及兼性厌氧菌有着不同程度的影响,其中对牛链球菌影响最大,从系统发育分析可知所分离细菌虽未形成新的细菌进化枝,但牛链球菌和嗜热链球菌的核苷酸序列仍发生了多处碱基突变。

In order to study the effect of dietary on the bacteria in the rumen of cows, nine different concentrate diets were used to feed Holstein cows during the dry period. Partial aerobe and facultative anaerobe were isolated, identified and detected. Five health cows were fed continuous- ly in nine periods. The results showed that 56 strains of bacteria were isolated from the rumen fluid by artificial medium, and the 16S rDNA genes of 7 strains of representative bacteria were amplified by PCR. These bacteria were S. boris （A0625, A1212, 0131）, B. cereus （0113）, B. licheniformis（ O091） , B. pumilus（ O083 ） and S. thermophilus（ 0123 ） respectively by sequence homogeneous analysis. At the same time, the quantities of S. boris, Bacillus and S. thermophilus were increased as the increase of concentrate. The results demonstrated that the dietary of different concentrate has different effects on the quantity of aerobe and facultative anaerobe in the rumen, and the quantities of S. boris was affected significantly. New evolutive branch of bacteria was not shaped by the phylogenetic analysis, however, there were several mutations in the nucleotide sequences of the S. boris and S. thermophilus.