The Study Of Qinghai-Tibet Plateau Soil Bacterial Diversity With Culture-dependent And Culture-independent Methods

In this paper, bacterial diversity of soil was explored with culture-dependent and culture-independent methods. Two ways were mainly used with the traditional methods of bacterial isolation and DGGE test to research the bacterial diversity and community dynamics around the railway on the Qinghai-Tibet Plateau of 23 different soil samples.2249 strains were isolated through the traditional methods with different media(R2A, halophilic, alkaliphilic, non-nitrogen etc.) from 23 different types of soil, and amplified 16S rRNA gene sequences of 1043 strains according to the Morphological of colony and geographical characteristics. Drew the phylogeny tree with the known of sequences alignment in the Genbank and the result showed that 1043 strains belonged to 83 groups. Among them, Pseudomonas, Bacillus, Arthrobacter and Streptomyces were the most common groups; This article is based on the the different of textures, land using patterns and climate characteristics of soil sampling, had a more systematic study on the number of bacteria, the major bacterial populations and the diversity of the different area.Soil samples were collected from 23 soil samples from the Qinghai-Tibet Plateau. Total DNA was extracted from those samples with the aid of bacterial universal primer and amplified by means of PCR and its product analyzed with the DGGE technique to explore diversity of bacterial communities. Seqence analysis of main bands in the DGGE patterns indicated unculture bacteria was the most frequently encountered general between 23 soil samples. Soil microbial diversity in Qinghai-Tibet Plateau was influenced by soil type, altitude and vegetation characteristics and other factors.The community isolated and cultured from Qinghai-Tibet Plateau railway region with 23 different soil samples compared with that obtained by DGGE atlas and the result found that the culture-independent approach detected a richer bacterial communities than that by culture-dependent method. and Uncultured bacterium was the most frequently encountered general between 23 soil samples. Pseudomonas, Bacillus, Arthrobacter, Streptomyces were the most frequently encountered generas in the culture-dependent collection. However, 16S rRNA sequence analysis of main bands in the DGGE patterns of the same sample indicated that Uncultured bacterium, Sinorhizobium, Acinetobacter, Xanthomonas were the dominant generas of bacterial communities. The results obtained by culture-dependent and culture-independent approaches were quiet distinct from each other.The strains of R43, R101, R720 from all isolated strains of Qinghai-Tibet Plateau soil samples, maybe the new species because the similarity were 97.4—97.7% in the NCBI Balst and belonged to Sphingomona vermicomposti and the habitats of the three strains were different with each other. Tested with the closest type strain ACCC05496=DSM21299~T by the test of polyphase sort method: morphology, physiology and biochemistry characteristics, API identify system, Biolog, analysing of fatty acid composes (MIDI), GCmol% and phylogenetic degeneration analysing of 16S rRNA gene sequence. The result showed that, R43, R101, R720 were the new species of the Sphingobium.