本文旨在研究内蒙古不同地区青贮玉米中乳酸菌菌群结构的变化。试验采用氯化苄方法提取青贮玉米中微生物基因组DNA，以P2f和P3r为引物，对扩增的目的片段，利用变性梯度凝胶电泳(PCR-DGGE)法研究不同地区青贮玉米中乳酸菌菌群结构。结果表明：3个地区9个牧场的青贮玉米中乳酸菌DGGE图谱相似性较高，大多数序列代表乳酸菌(lactic acid bacteria, LAB)类细菌，并以?-Lactobacillus 类最多；窖藏半年以上的青贮玉米中仍能发现Lactococcus、Weissella、Leuconostoc 3个球菌属菌存在。另外，10号条带与?-Acetobacter相似性达94%，4号条带与?-Lactobacillus相似性达93%，但仍不能鉴定到属的水平，这2株菌属于未培养的或者说是未经测序的菌株。

The project was conducted to study the distribution of lactic acid bacteria population in silage corn in different regions of Inner Mongolia. Microbial genome DNA in silage was carried out by benzyl chloride method, and target fragments were amplified with P2f and P3r as primers, then distribution of lactic acid bacteria population was analysed by denature gradient gel electrophoresis (PCR-DGGE) method. The results showed that DGGE profiles of lactic acid bacteria exhibited high homology in silage from 9 pastures of 3 regions. The majority of sequence standed for lactic acid bacteria; among lactic acid bacteria LAB sequence, content of ?-Lactobacillus ranked on the top of the list. Besides, it was found that there were 3 coccus (Lactococcus, Weissella and Leuconostoc) alive in the silages for more than half a year. In addition, the similarity between band 10 and ?-Acetobacter reached to 94%, and similarity between band 4 and ?-Lactobacillus was 93%; but the two strains could not be identified to the level of specie, which belonged to strains without culture or sequence.［Chinese Journal of Animal Nutrition, 2009，21(6):974-981］