Aeromicrobium lacus sp. nov., a novel actinobacterium isolated from a drinking-water reservoir.

An actinobacterial strain, designated CPCC 204604T, was isolated from a water sample collected from Sancha Lake, a drinking-water reservoir in Sichuan Province, south-west China. Cells were strictly aerobic, Gram-stain-positive, non-spore-forming and non-motile. Polyphasic taxonomic analysis indicated that galactose and ribose were detected as the diagnostic sugars in the whole-cell hydrolysates, and ll-diaminopimelic acid was the diagnostic diamino acid in cell-wall peptidoglycan. MK-9(H4) was the predominant menaquinone. The phospholipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unidentified phospholipid. The major fatty acids were C16 : 0, C16 : 0 2-OH, C18 : 1ω9c, C18 : 0 and 10-methyl C18:0. The genomic DNA G+C content was 71.2 mol%. In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 204604T formed a distinct clade with Aeromicrobium ponti DSM 19178T within the lineage of the genus Aeromicrobium, with the highest 16S rRNA gene sequence similarity of 98.3 % to its closest neighbour. On the basis of the genotypic and phenotypic data, we conclude that strain CPCC 204604T represents a novel species of the genus Aeromicrobium, for which the name Aeromicrobiumlacus sp. nov. is proposed with strain CPCC 204604T (=NBRC 112936T=DSM 105424T) as the type strain.

Allobranchiibius huperziae gen. nov., sp. nov., a member of Dermacoccaceae isolated from the root of a medicinal plant Huperzia serrata (Thunb.).

A Gram-stain-positive, non-spore-forming actinobacterial strain, designated CPCC 204077T, was isolated from the surface-sterilized root of a medicinal plant Huperzia serrata (Thunb.) collected from Sichuan Province, south-west China. The peptidoglycan type of strain CPCC 204077T was detected as A4α with an l-Lys-l-Ser-d-Asp interpeptide bridge. Galactose, glucose, rhamnose and ribose were the sugar compositions in the whole-cell hydrolysates. MK-8(H4) was the only menaquinone. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, one unidentified phospholipid and one unidentified glycolipid. The major fatty acid was iso-C16 : 0. The genomic DNA G+C content was 71.0 mol%. The phylogenetic tree based on 16S rRNA gene sequences showed that strain CPCC 204077T stood for a distinct lineage within the family Dermacoccaceaealongside the genera Branchiibius, Demetria and Barrientosiimonas, with the highest 16S rRNA gene sequence similarities to Branchiibius hedensis Mer 29717T (95.0 %), Calidifontibacter indicus PC IW02T (95.0 %), Barrientosiimonas humi 39T (94.9 %) and Demetria terragena HKI 0089T (94.7 %), and less than 94.7 % sequence similarities to all other species. Signature nucleotides in the 16S rRNA sequence showed that the strain contained the Dermacoccaceaefamily-specific 16S rRNA signature nucleotides and a genus-specific diagnostic nucleotide signature pattern. Combining the genotypic and phenotypic analyses, we propose that strain CPCC 204077T represents a novel species of a new genus in the family Dermacoccaceae with the name Allobranchiibius huperziae gen. nov., sp. nov. Strain CPCC 204077T (=NBRC 110719T=DSM 29531T) is the type strain of the type species.

Naumannella huperziae sp. nov., an endophytic actinobacterium isolated from Huperzia serrata (Thunb.).

An endophytic, short rod-shaped, non-motile and non-spore-forming actinobacterium, designated strain CPCC 204135T, was isolated from a surface-sterilized medicinal plant, Huperzia serrata (Thunb.), collected from Sichuan Province, south-west China. Strain CPCC 204135T was observed to grow at temperatures between 20 and 37 °C (optimum, 28-32 °C), at pH 6.0-9.0 (optimum, pH 7.0-8.0) and in the presence of 0-9.0 % (w/v) NaCl (optimum, 0-3 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CPCC 204135T belonged to the genus Naumannella, showing the highest level of 16S rRNA gene sequence similarity with Naumannella halotolerans DSM 24323T (97.2 %), the only species of the genus Naumannella in the family Propionibacteriaceaewith avalidly published name. The DNA-DNA hybridization value between strain CPCC 204135T and N. halotolerans DSM 24323T was 20.1±1.8 %, which is far below the accepted 70 % threshold for species delineation. The cell-wall hydrolysates contained ll-diaminopimelic acid, alanine, glycine and glutamic acid, with the peptidoglycan type of A3γ. Diphosphatidylglycerol, phosphatidylglycerol, an unidentified phospholipid, one unidentified aminolipid, one unidentified polar lipid and several kinds of glycolipids were detected in the polar lipids profile. MK-9(H4) was identified as the predominant menaquinone. The major cellular fatty acids (>10 %) were anteiso-C15 : 0 and iso-C16 : 0. The G+C content of the genomic DNA of strain CPCC 204135T was determined to be 71.8 mol%. On the basis of phylogenetic analysis, and phenotypic and chemotaxonomic characteristics, we concluded that strain CPCC 204135T represents a novel species of the genus Naumannella, for which the name Naumannella huperziae sp. nov. is proposed, with strain CPCC 204135T (=DSM 101717T=NBRC 111773T) as the type strain.

Spirosoma lacussanchae sp. nov., a phosphate-solubilizing bacterium isolated from a freshwater reservoir.

A phosphate-solubilizing bacterium, designated CPCC 100624T, was isolated from a freshwater reservoir in south-west China. The 16S rRNA gene sequence comparison of strain CPCC 100624T with the available sequences in the GenBank database showed that the isolate was closely related to members of the genus Spirosoma. In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 100624T formed a stable phylogenetic subclade with Spirosoma soli MIMBbqt12T within the genus Spirosoma, which indicated that strain CPCC 100624T could be identified as a member of the genus Spirosoma. The strain grew at 10-40 °C (optimum 30 °C), at pH 6.5-8.0 (optimum pH 7.0-7.5) and in the presence of 0-5 % (w/v) NaCl (optimum 0-1 %). MK-7 was detected as the main menaquinone, with a minor amount of MK-7(H6) in its menaquinone system. Cells contained summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), C16 : 1ω5c and iso-C15 : 0 as the major fatty acids. The polar lipids of strain CPCC 100624T contained phosphatidylethanolamine, one unidentified aminolipid, two aminophospholipids and three unidentified lipids. The genomic DNA G+C content was 49.3 mol%. On the basis of the above taxonomic data and differences in physiological characteristics from the closely related type strains, strain CPCC 100624T represents a novel species of the genus Spirosoma, for which the name Spirosoma lacussanchae sp. nov. is proposed. The type strain is CPCC 100624T (=NBRC 111852T=DSM 101771T).

Modestobacter lacusdianchii sp. nov., a Phosphate-Solubilizing Actinobacterium with Ability to Promote Microcystis Growth.

A novel actinobacterium, designated strain JXJ CY 19T, was isolated from a culture mat of Microcystis aeruginosa FACHB-905 collected from Dianchi Lake, South-west China. 16S rRNA gene sequences comparison of strain JXJ CY 19T and the available sequences in the GenBank database showed that the strain was closely related to Modestobacter marinus 42H12-1T (99.1% similarity) and Modestobacter roseus KLBMP 1279T (99.0%). The isolate had meso-diaminopimelic in the cell wall with whole-cell sugars of mannose, rhamnose, ribose, glucose, galactose, and arabinose. The menaquinone detected was MK-9(H4), while the major cellular fatty acids include C17:1 ω8c, C15:0 iso, C15:1 iso G and C16:0 iso. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The DNA-DNA hybridization values between strains JXJ CY 19T and the closely related type strains Modestobacter marinus CGMCC 4.5581T and Modestobacter roseus NBRC 108673T were determined to be 50.8 ± 0.8% and 44.1 ± 1.7%, respectively. The DNA G+C content was 71.9 mol%. On the basis of the above taxonomic data and differences in physiological characters from the closely related type strains, strain JXJ CY 19T was recognized as a novel species of the genus Modestobacter, for which the name Modestobacter lacusdianchii sp. nov. (JXJ CY 19T = KCTC 39600T = CPCC 204352T) is proposed. The type strain JXJ CY 19T can solubilize calcium phosphate tribasic (Ca3(PO4)2), phytin and L-α-phosphatidylcholine. The phosphate-solubilizing property of the novel actinobacterium could be a possible factor for the increase in growth of Microcystis aeruginosa FACHB-905 in ecosystem where the amount of available soluble phosphate is limited such as Dianchi Lake.

Jatrophihabitans huperziae sp. nov., an endophytic actinobacterium isolated from surface-sterilized tissue of the medicinal plant Huperzia serrata (Thunb.).

A novel endophytic actinobacterium, designated strain CPCC 204076T, was isolated from surface-sterilized tissue of the medicinal plant Huperzia serrata (Thunb.) collected from Sichuan Province, south-west China. The taxonomic position of the isolate was investigated by a polyphasic approach. The strainwas aerobic, Gram-stain-positive, non-motile, non-spore-forming and rod-shaped. Growth was observed at 10-37 °C, at pH 5.0-10.0 and with 0-3.0 % (w/v) NaCl. The polar lipid fraction consisted of diphosphatidylglycerol, a phospholipid, an aminolipid, a glycolipid, an aminophospholipid and phosphatidylinositol. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid and the peptidoglycan was of type A4γ. The menaquinone system consisted of MK-9(H4) and MK-8(H4). The major cellular fatty acids (>10 %) were iso-C16 : 0 and anteiso-C17 : 0. The genomic DNA G+C content of strain CPCC 204076T was found to be 71.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that CPCC 204076T belongs to the genus Jatrophihabitans with highest sequence similarity to Jatrophihabitans endophyticus DSM 45627T (96.5 %), Jatrophihabitans soli DSM 45908T (96.5 %) and Jatrophihabitans fulvus JCM 30448T (96.1 %), and much lower similarities (<95.0 %) to other available 16S rRNA gene sequences from validly described pure cultures. However, DNA-DNA hybridyzation values between strain CPCC 204076T and the three recognized Jatrophihabitans species were 31±3.1 % (J. endophyticus DSM 45627T), 33±2.9 % (J. soli DSM 45908T) and 37±1.7 % (J. fulvus JCM 30448T), which were all far below the recommended cut-off value of 70 %. The phenotypic and genomic characteristics distinctly indicated that strain CPCC 204076T represents a novel species of the genus Jatrophihabitans, for which the name Jatrophihabitans huperziae sp. nov. is proposed. The type strain is CPCC 204076T (I13A-01604) (=DSM 46866T=NBRC 110718T).

Herbihabitans rhizosphaerae gen. nov., sp. nov., a member of the family Pseudonocardiaceae isolated from rhizosphere soil of the herb Limonium sinense (Girard).

The taxonomic position of an actinobacterium, designated CPCC 204279T, which was isolated from a rhizosphere soil sample of the herb Limonium sinense collected from Xinjiang Province, China, was established using a polyphasic approach. Whole-cell hydrolysates of strain CPCC 204279T contained galactose and arabinose as diagnostic sugars and meso-diaminopimelic acid as the diamino acid. The muramic acid residues in the peptidoglycan were N-acetylated. The predominant menaquinone was MK-9(H4). The phospholipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The major fatty acids were iso-C16 : 0, iso-C16 : 0 2-OH, C16 : 1ω9c, iso-C16 : 1 and C16 : 0. The genomic DNA G+C content was 73.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CPCC 204279T should be placed in the family Pseudonocardiaceae, in which the strain formed a distinct lineage next to the genus Actinophytocola. Signature nucleotides in the 16S rRNA gene sequence showed that the strain contained the Pseudonocardiaceae family-specific 16S rRNA signature nucleotides and a genus-specific diagnostic nucleotide signature pattern. The combination of phylogenetic analysis and phenotypic characteristics supported the conclusion that strain CPCC 204279T represents a novel species of a new genus in the family Pseudonocardiaceae, for which the name Herbihabitans rhizosphaerae gen. nov., sp. nov. is proposed. Strain CPCC 204279T (=NBRC 111774T=DSM 101727T) is the type strain of the type species.

Microlunatus nigridraconis sp. nov., an actinobacterium from rhizosphere soil.

An actinobacterium, designated strain CPCC 203993T, was isolated from a rhizosphere soil sample collected from Heilongjiang Province, northeast China, and was characterized using a polyphasic taxonomy approach. Cells of the strain were Gram-stain-positive, non-motile and non-endospore-forming cocci. The 16S rRNA gene sequence comparison of strain CPCC 203993T with members of the genus Microlunatus yielded 93.9 % to 97.8 % similarities. In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 203993T was affiliated to the clade of the genus Microlunatus next to Microlunatus parietis DSM 22083T, while the DNA-DNA hybridization value of 31.5 % (±1.8 %) between strain CPCC 203993T and Microlunatus. parietis DSM 22083T was far below 70 %. This result indicated that strain CPCC 203993T represented a different genomic species from M. parietis. Chemotaxonomically, the strain contained ll-2,6-diaminopimelic acid as the diagnostic diamino acid, MK-9(H4) as the only menaquinone, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, three unidentified glycolipids and one unidentified phospholipid in the polar lipids extracts, and anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0 as the major cellular fatty acids, without mycolic acids. The genomic DNA G+C content was 64.04 mol%. The above evidence from the polyphasic study merit the recognition of strain CPCC 203993T as a representative of a novel species of the genus Microlunatus, for which Microlunatus nigridraconis sp. nov. is proposed. The type strain is CPCC 203993T (=DSM 29529T=NBRC 110715T=KCTC 29689T).