Screening Of High Sugar Strains And Microbial Taxonomic Study Of Novel Species,Which All Were Isolated From Extreme Environment Of West China

The research objects were some microorganisms, which were isolated from several different extreme environment of west China. In this study, two suspected novel strains isolated from permafrost region of Qinghai-Tibet plateau, were analysed by some polyphasic taxonomy methods. Phylogenetic, phenotypic and chemotaxonomy analysis were carried out in order to confirm the taxonomical position of two novel species. Several high glucose strains were isolated through specific microbial screening process, and the environmental samples were from Aiding salt lake valley and desert of Sinkiang.Strain AT representing a novel Gram-negative, obligately aerobic, bacteriochlorophyll a-containing bacterium of the a-4 subgroup of the Proteobacteria was isolated from permafrost soil of Kunlun mountains gap, Qinghai-Tibet plateau. Cells were non-motile and rod-cocci-shaped and formed brown-pigmented colonies. According to the absorption spectrum, carotenoids and two different photosynthetic light-harvesting complexes, an LHI complex and a B800-835-type peripheral LHII complex, were present in the cells. The strain was oxidase-negative and catalase-positive. The predominant fatty acids of strain AT were summed feature 3 (C16:1?7c and/or C16:1?6c), C17:1?6c and summed feature 8 (C18:1?7c and/or C18:1?6c). The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, unidentified phospholipid, two glycolipids, and sphingoglycolipid. The major respireatory quinone was ubiquinone-10, whereas ubiquinone-9 was present in smaller amounts. The 16S rRNA gene sequence similarity to the closest phylogenetic relative Polymorphobacter multimanifer JCM 18140T was 97.5%. DNA-DNA relatedness (?Tm) between strain A and P. multimanifer was 12.4?. The G+C content of the genomic DNA of strain D40PT was 67.4 mol%. Accordingly, the strain was identified as a novel species, and the name Polymorphobacter fuscus sp. nov was proposed. The type strain is A (=CGMCC 1.12714T=JCM 19740T). Emended descriptions of the genus Polymorphobacter is also proposed.A Gram-negative, rod-shaped, non-motile, non-spore forming, aerobic, orange-pigmented bacterium was isolated from soil sample of the Hoh Xil basin, China, designated strain BT. Strain BT grew optimally at 25?, pH 7.0-7.5 and NaCl concentration of 0-1%(w/v). Phylogenetic analysis based on 16S rRNA gene sequences testified that the strain BT was one of the genus Sphingomonas. The 16S rRNA gene sequence similarity to the closest phylogenetic relative Sphingomonas fennica was 97.1%. The DNA-DNA hybridization homology with Sphingomonas fennica DSM 13665T was 45.3%. The DNA G+C content of the novel strain was 65.3 mol%. The isolate contained Q-10 as the only respiratory quinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, sphingoglycolipid, phosphatidylcholine and phosphatidylethanolamine. C18:1?7c and C16:1?7c were the major fatty acids. On the basis of the polyphasic evidence presented, strain BT was identified as a novel species, and the name Sphingomonas arantia sp. nov was proposed. The type strain is BT (=CGMCC 1.127021 =JCM19855T).It is difficult to select high glucose resistance strains from desert environmental samples (4# and 5#). However some high glucose resistance strains which belong to the genus Bacillus, were isolated from salt lake valley of environmental samples (1#,2# and 3#).