The Isolation And Identification Of Moderately Halophile Bacterium And Extremly Halophile Archaeon

Along with more strenth inputted into the study about halophile in recent years, we not onlyisolated more and more new strains, but also understood the halophilic metobolism more deeplyand found more interesting characteristics of new strains, made us realize the potentialapplication values of halophile. Especially those moderately halophile bacterium, which adaptgreat range of salt concentration, and extremly halophile archaeon, grew only in the environmentwith extremly high salt concentration, both of them have their own unique advantages and attractmore people work hard to isolate more special strains with great biotechnological potential.In the work, samples were collected from the hypersaline environment of Lianyunguang,Jiangsu province and Yuncheng, Shanxi province, and carried out the studying about theisolation and identification of halophiles. Furthermore, study on systematic taxonomy of isolatedhalophiles had been done using technology including cultural condition determinations,morphological characteristic observations, physiological and chemical tests, and phylogeneticanalysis of 16S rDNA gene sequences.Through the light microscope observation, 10 purple moderately halophile bacterium strainswere picked and gained their 16s rDNA sequences. After doing alignment with 16s rDNAsequences in GenBank, we preliminarily got their phylogentic positions and found that: strainLYG 24, LYG 30, LYG 1 maybe belong to the genus of Rhodovibrio, and have the nearestrelationship with Rhodovibrio salinarium; strain LYG 4C maybe belong to the genus ofHalomonas; strain LYG 10 and BX 104 have the nearest connection with the strain Salisaetalonga; strain LYG 20 and LYG 9 maybe belong to Alkalispirillum; strain LYG BX6 maybebelong to Marinobacter; as to strain LYG 8018, it has a seperated branch in the phylogenetic tree,doesn't belong to any genus, and has the similarity of 87% with strain Rhodovibrio salinarium.Further studying about the strain LYG 8018, it is a Gram-negative vibrio, growing best at 40℃,the optimum concentration of NaCl is 12% (w/v), the optimum pH is 7.0, catalase- andoxidase-positive, can reduce nitrate. By means of phenotypic, biochemical and molecularbiological characteristics, we identified this strain maybe belong to the family Rhodospirillaceaeof moderaely halophile bacerium as a novel species in a novel genus, and wanted to designatedit as Salinicurvata lianyungangensis gen.nov.sp.nov..7 extremly halophile archaeon strains were isolated, and sequenced 16S rDNA genesequenc of 2 special strains, and compared with sequences in GenBank, preliminarily thinkthat strain DX 111 maybe belong to the genus of Halorubrum, with the nearest relative Halorubrum lacusprofundi; strain DX 114 has a isolated branch in the phylogenetic tree, doesn'tbelong to any genus, and has the similarity of 83% with genus Halorubrum. Further studyingshowed that strain DX 114 was a Gram-negative rod, growing best at 40℃, the optimumconcentration of NaCl is 3.4M, the optimum pH is 7.5, and the optimum concentration of Mg2+is 0.4M, catalase- and oxidase-positive, can reduce nitrate. From phenotipic, biochemical andmolecular biological characteristics, we identified this strain maybe belong to the familyHalobacteriaceae of extremely halophile archaeon as a novel species in a novel genus, andwanted to designated it as Haloroseus lianyungangenisis gen. nov., sp.nov..As to the other 130 strains isolated from the salt ponk of Lianyungang and the salt lake ofYuncheng, we are going to screen special strains through phenotypic identities, gain their 16SrDNA gene sequences through PCR, and identify the physological and biochemicalcharacteristics of those special strains. In a word, expect to gain more useful halophile.