Phylogenetic Characterization of Bacterial Populations in Different Layers of Oak Forest Soil

Department of Microbial & Nanomaterials, Mokwon University, Daejeon 302-729, Republic of Korea(Received April 24, 2015; Accepted June 19, 2015)ABSTRACT: We have examined the correlation between the physicochemical and microbiological environment variables for the different layers of oak forest soil in Mt. Gyeryong, Korea. The result shows that there is a high correlation in the environment variable s between the soil parameters of the fermented (F) layer and humus (H) layer. In particular, the pH level in the F layer shows a high correla tion with C and N, while the various organic acids of the H layer turns out to be closely correlated with soil bacteria density. As we evaluated phylogenetic characteristics of bacterial populations by DGGE analysis with DNA extracted. Total of 175 bands including 43 band s from litter (L) layer, 42 bands from F layer, 43 bands from H layer and 47 bands from rhizosphere (A) layer were selected as the maj or DGGE band of oak forest soil. Based on the 16S rRNA gene sequences, 175 DGGE bands were classified into 32 orders in 7 phylum. 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, it also showed that approximately 50% of the total microbial population in different layers is α-proteobacteria , which indicates that they belong to the dominant system group. In particular, Rhizobiales , Burkholderiales and Actinobacteriales were observed in all the seasons and layers of oak forest soil, which confirms that they are the indigenous soil bacterial community in oak forest soil.Key words: bacterial populations, DGGE, oak forest soil, phylogeny