Pyrosequencing-based assessment of bacterial community structure in different layers of the oak forest soil
1Department of Microbial & Nano Materials, Mokwon University
In the previous study, biodiversity of bacterial community in different layers of oak forest soil were analyzed by 16S rRNA-DGGE. Soil bacterial community composition and diversity showed significant differences between the different layers of forest soil. In the present study we used pyrosequencing-based analysis of the V2-V3 16S rRNA gene region to identify changes in bacterial diversity and community structure in different layers of the oak forest soil. Total 29,676 reads were obtained from 4 samples and used for taxonomic classification and OTU distribution analysis. Bacterial diversity was more phylum rich in F layer and H layer than in litter (L) layer and rhizosphere (A) layer. The dominant taxonomic groups across all samples (more than 5% of all sequences) were Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes and Gemmatimonadetes. Proteobacteria is the largest bacterial phylum in all samples, with a marked shift of the proportions of α-, β-, γ– and δ–proteobacteria. Furthermore, it also showed that approximately 30% of the total microbial population in different layers is α–proteobacteria, which indicates that they belong to the dominant group. The heat map was analyzed in order to compare the quantity of the base sequences of each order and based on the clustering of the different layers of oak forest soil, the result confirms that the F layer and H layer belong to a different cluster from that of L layer and A layer. Furthermore, bacterial community structure was largely driven by physicochemical and microbiological environment variables for the different layers.
keywords:bacterial community,biodiversity,oak forest soil,proteobacteria ,pyrosequencing