Polyphasic Taxonomic Identification Of Thermophilic Bacteria And One Method For Mass Screening On Bacteria Resources

In this study,9 bacteria were isolated from Guhai hot spring (44°45’N.88°49’E) in Jimsar county, Xinjiang province. Based on the phylogenetic analysis and the result of sequence alignments, three bacteria of them shared the same 16S rRNA sequence with Brevibacterium halotolerans and belong to the genus Brevibacterium.16S rRNA sequence of other 3 bacteria were the same. The result of sequence alignments showed that they shared the highest 16S rRNA gene sequence similarity value of 92.5% with strain Thermovum composti KCTC 23707T. Selected the strain GU51T as the representative strain of this three strains to study. The last three strains also shared same 16S rRNA sequence. The result of sequence alignments showed that they shared the highest 16S rRNA gene sequence similarity value of 96.8% with strain Chelativorans multitrophicus DSM 9103T. Strain GU4T was selected as the representative strain of this three strains to study. We used the polyphasic taxonomic method to identify strain GU51T and GU4TThe other strictly aerobic bacterium isolated from the Puge hot spring located in south-western geothermal area of China by Xin-Qi Zhang, named 3nP4T was also discussed in this paper. Strain 3nP4T was Gram-stain-positive, motile and spore-forming bacterium. Grew at 38-66 ℃ (optimum 57-60 ℃), at pH 6.0-9.3 (optimum 7.0-7.5) and with 0-4%(w/v) NaCl (optimum 0-0.5%). Phylogenetic analysis of 16S rRNA gene sequences, as well as DNA-DNA relatedness values, indicated that the isolate represents a novel species of the genus Anoxybacillus, related most closely to Anoxybacillus voinovskiensis DSM 12111T. Strain 3nP4T had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and one unidentified phospholipid as major polar lipids and iso-Cis:o and iso-C17:0 as major fatty acids. The mean DNA G+ C content of strain 3nP4T was 39.2±0.95 mol%. A distinctive characteristic of the novel isolate was its extreme reliance on vitamin mixture or yeast extract for growth. Based on data from this taxonomic study using a polyphasic approach, strain 3nP4T is considered to represent a novel species of the genus Anoxybacillus, for which the name Anoxybacillus vitaminiphilus sp. nov. is proposed. The type strain is 3nP4T (CGMCC 1.8979T=JCM 16594T).On the basis of polyphasic taxonomy study about strains, for further research, we build strain screening platform to select the functional bacteria. With the process of strain activation, transfer, freeze dry with 96-well plates and verification, we got 470 strains on more than 25 96-well plates. The preliminary study to select the strain which can produce alkaline amylase and have the potential to resist cancer have been conducted with this platform. More functional strain screening studies will be performed in the future with this platform.