Isolation, Identification Of Microorganisms From High Saline Environments And Research On Treatment Of Saline Wastewater By Using Halophiles

Halophile is a kind of microorganisms which live in high saline environments, such as salt lakes and the ocean. Their special biological characteristics have a great research and application value, and they have been taken particularly interests in recent years. In this study, we investigated the biodiversity of cultured halophiles from Ayakekum Lake in Xinjiang region, salterns in Zhejiang and the East China Sea. A systematic study had been conducted on the taxonomy of three isolates. We also constructed a high efficiency halophilic bacteria group to treat the saline wastewater.We isolated 454 halophilic and halotolerant microorganisms from Ayakekum Lake in Xinjiang region, salterns in Zhejiang and the East China Sea and 139 of them have been taken into 16S rDNA study. Phylogenetic analysis based on 16S rRNA genes of these strains indicated that members in this three kind of saline environments are different. About 65% of the isolates from Ayakekum Lake were halophilic archaea, and members of Halorubrum share the greatest proportion. As for saltern samples, about 43% of the isolates were Firmicutes members, and members of the genus Halobacillus were more than the other groups. Only 31% of isolates were archaea. Isolates from sea water samples showed highest biodiversity. All of the isolates from sea water sample were bacteria, and 67.5% of them belong to Proteobacteria. Number of isolates belong to the genus Marinobacter were the biggest among isolated sea bacteria, followed by the Halomonas species.Several isolates show long distance from their closely related species, and the morphology, physiology, biochemical features, polar lipid composition, 16S rRNA genes and DNA-DNA relatedness of three strains, FS24, 908115 and LY2, were characterized in order to elucidate their taxonomic status. Our results indicate that these strains represent three novel species. The names Citricoccus zhacaiensis sp. nov., Marinobacter donghaiensis sp. nov.and Alcanivorax ningii sp. nov. are proposed. Most microorganisms in wastewater treating systems can not grow in high saline environment, so when saline wastewater was charged in to wastewater treating system, the treating efficency is usually very low. One solution to this problem is to dilute high saline wastewater to a salt concentration lower than 1%, then the wastewater treating system can work with a high efficency, but this require large quantity of freshwater. Halophilic microorganisms formed particular Adaptation to saline invironments during the process of evolution and show potential in saline wastewater treatment. In this study, strains were isolated from saline environments and applied to wastewater treating systems. High efficency bacteria group was conducted, and the member of this group can not only remove COD of wastewater, but aslo raise the pH of the wastewater. The ability to raise pH value is important for wastewater with low pH, such as the wastewater from production of pickled vegetables.China has various kinds of high saline environments, and lots of unknown halophilic microorganisms are still waiting for exploration. As halophilic microorganisms are special in physiology, besides the application in wastewater treatment, they might be expected to have enzyme repertoires that are so far unprospected and potentially interesting for biocatalysis and the enzymatic biosynthesis of fine chemicals.