Taxonomic Analysis Of Marine Novel Bacteria And Phosphate-solubility Of A Phosphate-dissolving Bacterium

Marine bacteria distribute in different environments, such as sea water, sea sediment, marine plants and animals, et al. ~The specificity and diversity of marine environments endowed marine bacteria with diversities on species, physiology, metabolism and ecological functions.Marine bacteria diversity can provide mankind with specific marine natural products, health foods, and biological materials. ~Therefore, the marine bacteria in different environments are studied in this research, which has theoretical and practical significance for further understanding and developing the usage of marine bacteria.Microbial physiological and biochemical technologies were used to study bacteria isolated from different environments, and three novel bacteria were studied and the Phosphate-solubility of a phosphate-dissolving bacterium were analysised. ~The main results are as follows:1. Isolation and identification of Sunxiuqinia elliptica gen. nov., sp. nov. DQHS4~T: ~Three novel aerobic, elliptic bacteria, designated DQHS4~T, DQHS8 and DQHS15, were isolated from sediment of a seashore pond for sea cucumber culture in Jimo of Qingdao, east coast of China. DNA–DNA hybridization experiment revealed high-value (>85 %) relatedness among these three novel isolates and suggested that these strains constituted a single species. Comparative 16S rRNA gene sequence analysis indicated that these bacteria had a less than 90% similarity to all described species of the phylum Bacteroidetes, and the most close relative of the three isolates was Prolixibacter bellariivorans F2~T, sharing only 89.6% sequence similarity. Based on the distinct phylogenetic position and combinations of genotypic, phenotypic and chemotaxonomic characteristics, these three strains were considered to represent a novel species of a new genus in the phylum Bacteroidetes, for which the name Sunxiuqinia elliptica gen. nov., sp. nov. was proposed. ~The type strain of Sunxiuqinia elliptica sp. nov was DQHS4~T (=CGMCC 1.9156~T = NCCB 100301~T= LMG 25367~T).2. ~Taxonomic analysis of Cohaesibacter marisflavi sp. nov. DQHS21~T:A Gram-negative, catalase-negative, oxidase-positive, rod-shaped bacterium, strain DQHS21~T, was isolated from sediment of a seashore pond for sea cucumber culture in Jimo of Qingdao, east coast of China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain DQHS21~T belonged to the genus Cohaesibacter, sharing the highest sequence similarity (96.1%) with Cohaesibacter gelatinilyticus CL-GR15 while the similarity with other strains was all below 93.0 %. ~The cellular fatty acids mainly consisted of C 18:1ω7c (60.68 %), C18:0 (17.76 %), C16:0 (8.47 %) and C16:1ω7c/ω6c (5.99 %), which together accounted for 92.9 % of the total fatty acids. Ubiquinone 10 was the major quinone. ~The G+C content of the chromosomal DNA of strain DQHS21 ~T was 55.2 mol%. ~The combined genotypic and phenotypic data showed that strain DQHS21~T represented a novel species of the genus Cohaesibacter, for which the name Cohaesibacter marisflavi sp. nov. was proposed, with the type strain DQHS21~T (=CGMCC1.9157~T= NCCB 100300~T).3. Isolation of a phosphate-dissolving bacterium YCWA18 and its phosphate- solubility analysis: A moderate halophilic phosphate-dissolving bacterium, named YCWA18, was isolated from the sediment sampled at Daqiao saltern in Jimo of Qingdao, east coast of China. ~The results showed the strain was gram negative, required aerobic conditions for growth and grew well with an optimum concentration at 8% NaCl (W/v) and tolerated up to 20% NaCl. Growth occurred at temperatures of 15-42°C(optimal growth at 28°C) and pH 3.0-9.0 (optimal growth at pH 7.0–8.0).16S rRNA analysis revealed that its sequence sharing 98.573% similarity to Kushneria sinocarnis (CC~TCC AB209027~T). Based on the phenotypic distinctiveness and 16S rRNA sequence evidence, it was proposed that YCWA18 can be classified as genus Kushneria. ~The strain showed high phosphate-dissolving ability for Ca3(PO4)2 with the capacity of 187~283.16μg/mL in Ca3(PO4)2 liquid medium at 20~32°C and 47.52μg/mL in lecithin liquid medium. And its activity for Ca3(PO4)2 was higher than for lecithin.