Bacterial Diversity Of Different Degenerate Grassland In Inner Mongolia

In this paper, the total DNA of microorganisms was extracted directly from different degenerate grassland in Inner Mongolia. Means of molecular biology was used to study the changes of the structure and the space distribution of soil microbial community, which in different degenerate grassland.DGGE was used to study 16S rRNA (V3 region) of soil microbial community, the result shows that the structure of soil microbial community changed a lot, when the degeneration of grassland is progressing, especially the structure of soil microbial community in surface lamina; The structure of soil microbial community in podzolic horizon of hypo-surface lamina of the grassland degenerated heavily, is similar to soil microbial community in illuvial horizon of the typical grassland and the grassland degenerated lightly. Also, the amount of low G + Cmol% microbe reduced as the thickness of soil layer increased.The phylogenetic affiliation of soil microbe in surface lamina of different degenerate grassland was determined by 16S rDNA sequencing of cloned DNA fragments. The sequences of the clone in the typical grassland, the grassland degenerated lightly and the grassland degenerated heavily were mainly attributed to Firmicutes, Proteobacteria and Actinobacteria, respectively. Bacillus is the dominant species of the three soil samples.DGGE analysis of soil microbe, which obtained from surface lamina of different degenerate grassland treated by some pretreatment, shows that the structure of soil microbial community in the grassland degenerated heavily had the least change, and catalase made diversity of the soil microbe increased remarkable.