Diversity Of Halophilic Bacteria In YanJing Hot Salt Well

Several bacterial strains were isolated from two hot salt wells with temperature about of 36℃(1^#) and 47℃(2^#). The hot salt wells are located at the side of Lancang River in the Tibet Autonomous Region. The salt concentration of the two hot salt wells was about 6%-6.3%, the pH was about 6.5. Two wells contain Na⁺, Cl^-, K⁺, Mg²⁺, Ca²⁺ and SO₄^2-, among these ions the concentrations of Na⁺ and Cl^- were the highest. Based on the salt compositions, these two hot salt wells belong to thalassohaline environments.Totally 21 bacterial strains were isolated from salt wells. Except one strain was orbicular, the rests strains were rodshaped, and most of them were Gram negative. All strains could grow at 13℃, but could not grow at 4℃and 60℃. Six strains could grow at 45℃, the rests could grow even at 55℃. The growth pH range was between 6 and 9. Four strains could tolerate 30%NaCl, while all isolates could not grow without NaCl. Two strains could grow at 55℃and could tolerate 30% NaCl. Based on physiological and biochemical characteristics and phylogenetic analysis of 16S rRNA gene, three strains isolated from 1^# salt well were identified as Thalassobacillus genus, others strains from 1^# well belong to Marinobacter genus. Eleven strains isolated from 2^# salt well were identified as Thalassobacillus genus, Marinobacter genus, Paraliobacillus genus, Halomonas genus, Idiomarina genus and Chrmohalobacter genus respectively. Therefore, 2^# salt well showed more diversity than 1^#.The 16S rRNA gene sequences of six strains were submitted to Genbank and obtained accession numbers. Morphological characteristics, G+C content, physiological and biochemical characteristics were investigated, phylogenetic analysis were completed by comparation of these strains with corresponding standard strains. Strain YJ0201, strain YJ0238 and strain YJ0239 were identified as a strain of Thalassobacillus devorans,Idiomarina zobelli and Chromohalobacter salexigens respectively. Our data suggest that three potential novel species of the genus of Marinobacter,Paraliobacillus and Halomonas were proposed.This is the first report on the study of high-temperature and high-salt microbial diversity domestically. In this paper, the microbial diversity of the two hot salt well was studied. It has provided useful resource for exploiting and utilizing extramophiles. It also provides research material and information for further studies in this area.