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An alpha-proteobacterial strain JXJ CY 53 T was isolated from the cyanosphere of Microcystis sp. FACHB-905 (MF-905) collected from Lake Dianchi, China. JXJ CY 53 T was observed to be an aerobic, Gram-stain-negative, oval shaped, and mucus-secreting bacterium. It had C18:1ω7c and C16:0 as the major cellular fatty acids, Q-10 as the predominant ubiquinone, and sphingoglycolipid, diphosphatidylglycerol, phosphatidylcholine, and phosphatidylmethylethanolamine as the polar lipids. The G + C content of DNA was 65.85%. The bacterium had 16S rRNA gene sequence identities of 98.9% and 98.7% with Sphingomonas panni DSM 15761 T and Sphingomonas hankookensis KCTC 22579 T, respectively, while less than 97.4% identities with other members of the genus. Further taxonomic analysis indicated that JXJ CY 53 T represented a new member of Sphingomonas, and the species epithet was proposed as Sphingomonas lacusdianchii sp. nov. (type strain JXJ CY 53 T = KCTC 72813 T = CGMCC 1.17657 T). JXJ CY 53 T promoted the growth of MF-905 by providing bio-available phosphorus and nitrogen, plant hormones, vitamins, and carotenoids. It could modulate the relative abundances of nonculturable bacteria associated with MF-905 and influence the interactions of MF-905 and other bacteria isolated from the cyanobacterium, in addition to microcystin production characteristics. Meanwhile, MF-905 could provide JXJ CY 53 T dissolved organic carbon for growth, and control the growth of JXJ CY 53 T by secreting specific chemicals other than microcystins. Overall, these results suggest that the interactions between Microcystis and its attached bacteria are complex and dynamic, and may influence the growth characteristics of the cyanobacterium. This study provided new ideas to understand the interactions between Microcystis and its attached bacteria. Key points: • A novel bacterium (JXJCY 53T) was isolated from the cyanosphere of Microcystis sp. FACHB-905 (MF-905) • JXJCY 53Tmodulated the growth and microcystin production of MF-905 • MF-905 could control the attached bacteria by specific chemicals other than microcystins (MCs) [ABSTRACT FROM AUTHOR]

Three Gram-stain-positive, aerobic, motile actinobacterial strains designated as CPCC 205119T, CPCC 205215, and CPCC 205251 were isolated from different biological soil crust samples collected from Tengger Desert, China. The 16S rRNA gene sequence comparison of these three strains showed they had almost identical 16S rRNA genes, which were closely related to members of the family Geodermatophilaceae , with the highest similarities of 96.3–97.3% to the species of Modestobacter. In the phylogenetic tree based on 16S rRNA gene sequences, these isolates clustered into a subclade next to the branch containing the species of Modestobacter lapidis and Modestobacter multiseptatus , within the lineage of the genus Modestobacter. The comparative genomic characteristics (values of ANI, dDDH, AAI, and POCP) and the phenotypic properties (morphological, physiological, and chemotaxonomic characteristics) of these isolates readily supported to affiliate them to the genus Modestobacter as a single separate species. For which, we proposed that the isolates CPCC 205119T, CPCC 205215, and CPCC 205251 represent a novel species of the genus Modestobacter as Modestobacter deserti sp. nov. CPCC 205119T (=I12A-02624=NBRC 113528T=KCTC 49201T) is the type strain. The genome of strain CPCC 205119T consisted of one chromosome (4,843,235bp) containing 4,424 coding genes, 48 tRNA genes, five rRNA genes, three other ncRNA genes, and 101 pseudogenes, with G+C content of 74.7%. The whole-genome sequences analysis indicated that this species contained alkaline phosphatase genes (phoA / phoD), phosphate transport-related genes (phoU , phnC , phnD , phnE , phoB , phoH , phoP , phoR , pitH , ppk , pstA , pstB , pstC , and pstS), trehalose-phosphate synthase gene (otsA), trehalose 6-phosphate phosphatase gene (otsB) and other encoding genes for the properties that help the microorganisms to adapt to harsh environmental conditions prevalent in deserts. Strains of this species could solubilize tricalcium phosphate [Ca3(PO4)2] and phytin, assimilate pyrophosphate, thiophosphate, dithiophosphate, phosphoenol pyruvate, 2-deoxy-d-glucose-6-phosphate, and cysteamine-S-phosphate. [ABSTRACT FROM AUTHOR]

Strain JXJ 0135(T), an anti-cyanobacterial actinomycete, was isolated from a soil sample collected from Lushan Mountain, south China, and identified by using polyphasic approach. Phylogenetic analysis of the near-complete 16S rRNA gene sequence indicated that strain JXJ 0135(T) belongs to the genus Streptomyces and exhibited distinct subclade and also highest similarity (98.6%) to Streptomyces scopuliridis RB72(T). The strain developed well-branched substrate and aerial mycelia, and produced spiral spore chains. Spores were elliptical and the spore surface was smooth. The strain contained LL-diaminopimelic acid with whole-cell sugars of mannose, rhamnose, glucose and galactose. Phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannosides, phosphotidylinositol dimannoside, an unidentified aminophospholipid and an unknown phospholipid. The menaquinones were MK-9(H6) and MK-9(H8). The major components of the fatty acids were anteiso-C15:0, iso-C16:0, anteiso-C17:0, iso-C15:0, C16:0, iso-C17:0 and iso-C14:0. The G+C content was 69.3 mol%. The DNA-DNA hybridization value between JXJ 0135(T) and S. scopuliridis RB72(T) was 41.2±1.4%. On the basis of the polyphasic data, strain JXJ 0135(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces lushanensis sp. nov. is proposed. The type strain is JXJ 0135(T) (=DSM 42121(T)=JCM 19628(T)=KCTC 29261(T)=KACC 17834(T)=NRRL B-24994(T)).

An actinomycete capable of lysing cyanobacteria, strain JXJ 0074(T), was isolated from a soil sample collected from Jiangxi province, south China, and characterized by using polyphasic taxonomy. The new isolate showed morphological and chemotaxonomic properties typical of members of the genus Streptomyces. Phylogenetic analysis of the near-complete 16S rRNA gene sequence indicated that strain JXJ 0074(T) should be affiliated to the genus Streptomyces and exhibited highest similarities to Streptomyces shenzhenensis DSM 42034(T) (98.99 %) and Streptomyces lucensis NBRC 13056(T) (98.60 %), while the similarities to other members of the genus are lower than 98.22 % similarity. However, the DNA-DNA hybridization values between strain JXJ 0074(T) and S. shenzhenensis DSM 42034(T) or S. lucensis NBRC 13056(T) were 46.2 ± 2.6 and 32.6 ± 3.1 %, respectively. Thus, on the basis of the polyphasic data, strain JXJ 0074(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces jiujiangensis sp. nov. is proposed. The type strain is JXJ 0074(T) (= BCRC 16953(T) = KCTC 29262(T)).

A novel filamentous bacterium, designated YIM 77831(T), was isolated from a geothermal soil sample collected at Rehai National Park, Tengchong, Yunnan province, south-west China. Growth occurred from 28 to 65 °C (optimum 50 °C), pH 6.0-8.0 (optimum pH 7.0). The strain formed branched substrate mycelia, endospores were produced on the substrate mycelium and aerial mycelium was not produced on any of the growth media tested. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YIM 77831(T) was affiliated with the family Thermoactinomycetaceae. The stain YIM 77831(T) contained meso-diaminopimelic acid in the cell wall. Whole-cell hydrolysates contained glucose, galactose, mannose, ribose and rhamnose. The polar lipids were phosphatidylmethylethanolamine, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid and four unknown phospholipids. The only menaquinone was MK-7. Major fatty acids were iso-C(15:0), anteiso-C(15:0) and anteiso-C(17:0). The G+C content was 55.6 mol%. On the basis of the morphological and chemotaxonomic characteristics as well as genotypic data, strain YIM 77831(T) represents a novel genus and species, Lihuaxuella thermophila gen. nov., sp. nov., in the family Thermoactinomycetaceae. The type strain is YIM 77831(T) (CCTCC AA 2011024(T) = JCM 18059(T)).