Diversity Of Culturable Bacteria From Qijiaojing Lake In Xinjiang And Their Ability To Produce Enzymes

This study is focus on the qijiaojing salt lake in Xinjiang province to determine the diversity of culturable bacteria and their ability to produce functional enzymes. Total fifteen soil saline samples were selected to isolate halotolerant/halophilic bacteria using the designed isolate media in this study. We identifed the classified position by the polyphasic taxonomy approach, and analysis the diversity of the salt bacteria in qijiaojing salt lake. Screening the functionable enzymes, we evaluate their amylase activities and protease activities in order to provide the experimental data for future exploitation of the isolated strains in the qijiaojing salt lake.For the strains isolated from the fifteen soil samples of the qijiaojing salt lake, after the purification and deduplication, we finally obtained eighty-six strains, we analysised their 16S rRNA gene sequences which can be classified them to the genus level. These eighty-six strains distributed in the thirteen genera, which including Gracilibacillus , Halomonas , Bacillus , Chelativorans , Chromohalobacter ,Tenuibacillus,Thalassobacillus, Halobacillus,Marinobacter,Staphylococcus,Brevibacillus,Solibacillus and Catellibacterium. Each genus contains the number of the strains are 1, 17, 13, 1, 1, 4, 5, 30, 1, 1, 1, 1 and 2, respectively. The results indicated that the genus Halobacillus had the largest numbers of strains. And there exist thirty-seven strains which had the 16S rRNA sequence similarity below 98.5%, thus these strains are preliminary determined as candidate new species which worth doing polyphasic taxonomy studies to determine their accurate taxonomic status.By using the polyphasic taxonomy approach, their morphology, chemotaxonomy, determination of G + C contents of DNA, 16S rRNA gene sequencing and phylogenetic analysis, and DNA–DNA hybridizations were performed for both strains YIM 93003 and YIM 94343 and related reference type strains. The results indicated that strains YIM 93003 and YIM 94343 represents two new different species of the genus Halomonas, designated as Halomonas qijiaojingensis sp. nov., Halomonas flava sp. nov., respectively.To test their enzymatic activity, we screened thirty-nine strains of them, which could grown on the media contained or above the 10% NaCl. And there were eighteen strains having amylase activity, eighteen strains having protease activity, five strains had both enzymatic activities and eight strains have no either enzymatic activity. The genus Halobacillus showed the most superiority in both enzyme activities. Our experimental results provided the scientific data for further screening high amylase and protease activities from halophilic or halotolerant strains isolated form hypersaline environments.The results in this study indicated that the culturable bacteria in the qijiaojing salt lake not only have the abundant biodiversity, but also have the enormous potential to obtain the amylase and protease, which provided a beneficial scientific evidence for the exploiting of the culturable bacteria resources.