Xiao-Mei Zhang

Nocardioides nanhaiensis sp. nov., an actinobacterium isolated from a marine sediment sample

A rod- to coccus-shaped, non-spore-forming actinobacterium, strain YIM M13091(T), was isolated from a marine sediment sample collected from the South China Sea and examined by a polyphasic approach to clarify its taxonomic position. This Gram-staining-positive, aerobic actinobacterium did not produce substrate mycelium and aerial hyphae, and no diffusible pigments were produced on the media tested. The optimum growth occurred at 30 °C, 1% (w/v) NaCl and pH 8.0. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Nocardioides, with low levels (≤96.2%) of sequence similarity with respect to Nocardioides kribbensis KSL-2(T) and other members of the genus Nocardioides. Whole-organism hydrolysates of the strain contained ll-2,6-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinone was MK-8(H4), with MK-8 in a minor amount. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, hydroxyphosphatidylinositol and phosphatidylcholine, were the main polar lipids detected, while iso-C(16 : 0) and C(18 : 1)ω9c were the major fatty acids. The G+C content of the genomic DNA was 68.5 mol%. Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the isolate represents a member of the genus Nocardioides, and the name Nocardioides nanhaiensis sp. nov. (Type strain YIM M13091(T) = JCM 18127(T) = CCTCC AA 2011020(T)) is proposed for the novel species.

Description of Streptomonospora sediminis sp. nov. and Streptomonospora nanhaiensis sp. nov., and reclassification of Nocardiopsis arabia Hozzein & Goodfellow 2008 as Streptomonospora arabica comb. nov. and emended description of the genus Streptomonospora.

Two actinomycete strains isolated from marine sediment samples, designated YIM M11335(T) (from the Indian Ocean) and 12A09(T) (from the South China Sea), were obtained and examined by a polyphasic approach. The two Gram-staining-positive, aerobic strains produced branched substrate mycelia and aerial hyphae that were not fragmented, and no diffusible pigment was produced on the media tested. At maturity, spore chains and single spores were formed on aerial hyphae and substrate mycelium, respectively. Whole-organism hydrolysates of both strains contained meso-diaminopimelic acid and the diagnostic sugars glucose and galactose. Their predominant menaquinones were MK-10(H4), MK-10(H6), MK-11(H4), MK-11(H6) and MK-11(H8) for strain YIM 11335(T) and MK-10(H4), MK-10(H6), MK-11(H4), MK-11(H6) and MK-11(H8) for strain 12A09(T). The polar lipids detected in the two strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phosphatidylcholine, an unknown phosphoglycolipid and several unknown glycolipids, phospholipids and polar lipids. The major fatty acids (>10%) were iso-C16 : 0 and C16:0 for strain YIM 11335(T) and iso-C16:0 for strain 12A09(T). The G+C contents of the genomic DNA of strains YIM 11335(T) and 12A09(T) were 70.7% and 74.4%, respectively. DNA-DNA hybridization relatedness values of these two isolates with the type strains Nocardiopsis arabia DSM 45083(T) and Streptomonospora halophila YIM 91355(T) supported the hypothesis they are representatives of two different species. Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the two isolates belong to the genus Streptomonospora of the family Nocardiopsaceae and that the type strain of N. arabia should be reclassified as a representative of Streptomonospora arabica comb. nov. The names proposed for the two novel species are Streptomonospora sediminis sp. nov. (type strain YIM M11335(T) = DSM 45723(T) = CCTCC AB 2012051(T)) and Streptomonospora nanhaiensis sp. nov. (type strain 12A09(T) = KCTC 29145(T) = CCTCC AB 2013140(T)), respectively. An emended description of the genus Streptomonospora is also proposed in the light of the new data.

Bacillus tianshenii sp. nov., isolated from a marine sediment sample

A novel Gram-stain-positive, motile, catalase- and oxidase-positive, aerobic, endospore-forming, peritrichous, rod-shaped bacterium, designated YIM M13235(T), was isolated from a marine sediment sample collected from the South China Sea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM M13235(T) belonged to the genus Bacillus. The strain grew optimally at 30 °C, pH 7.0 and in the presence of 2-4% (w/v) NaCl. meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. Strain YIM M13235(T) exhibited a menaquinone system with MK-7, and the major polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unknown phospholipids and one unknown glycolipid. The major fatty acids (>5%) were iso-C(15 : 0), anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(17 : 1)ω10c and summed feature 4 (anteiso-C(17 : 1) and/or iso-C(17 : 1)). The genomic DNA G+C content was 42.1 mol%. The DNA-DNA relatedness values between strain YIM M13235(T) and its close relatives (16S rRNA gene sequence similarities >97%) including Bacillus halmapalus DSM 8723(T), Bacillus horikoshii DSM 8719(T) and Bacillus zhanjiangensis JSM 099021(T) were 41%, 44% and 44%, respectively. On the basis of genotypic, phenotypic and DNA-DNA relatedness data, it is apparent that strain YIM M13235(T) represents a novel species of the genus Bacillus, for which the name Bacillus tianshenii sp. nov. is proposed. The type strain is YIM M13235(T) ( = DSM 25879(T) = KCTC 33044(T)).

Pseudonocardia sediminis sp. nov., isolated from marine sediment.

A Gram-stain-positive, aerobic actinomycete, designated strain YIM M13141(T), was isolated from a marine sediment sample from the South China Sea, and its taxonomic position was determined using a polyphasic approach. The strain produced branched substrate mycelium and aerial hyphae, but no diffusible pigments were produced on the media tested. At maturity, substrate mycelium was fragmented and spore chains were formed on aerial hyphae and substrate mycelium. Optimum growth occurred at 28 °C, 1-3% (w/v) NaCl and pH 7.0. Comparative analysis of the 16S rRNA gene sequence showed that the isolate belongs to the genus Pseudonocardia, showing highest levels of similarity with respect to Pseudonocardia sichuanensis KLBMP 1115(T) (97.1%), Pseudonocardia tetrahydrofuranoxydans K1(T) (97.1%) and Pseudonocardia kunmingensis YIM 63158(T) (97.0%). Whole-organism hydrolysates of the strain contained meso-diaminopimelic acid and the sugars galactose, glucose, mannose and arabinose. The predominant menaquinone was MK-8(H4). The polar lipids detected were diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylmethylethanolamine, phosphatidylethanolamine, two unknown phosphoglycolipids and two glycolipids. The major fatty acid was iso-C16 : 0. The G+C content of the genomic DNA was 73.1 mol%. DNA-DNA relatedness with P. tetrahydrofuranoxydans DSM 44239(T) was 42.8 ± 3.5% (mean±sd). Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the isolate represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia sediminis sp. nov. is proposed. The type strain is YIM M13141(T) ( = DSM 45779(T) = JCM 18540(T)).

Actinophytocola sediminis sp. nov., an actinomycete isolated from a marine sediment

A novel actinomycete strain, designated YIM M13705(T), was isolated from a marine sediment sample of the South China Sea and its characteristics were determined by a polyphasic approach. The slowly growing, Gram-stain-positive, aerobic strain produced branched substrate mycelium and aerial hyphae, and no diffusible pigment was produced on the media tested. At maturity, spore chains were formed on aerial hyphae and substrate mycelium was not fragmented. Whole-cell hydrolysates of the strain contained meso-diaminopimelic acid and galactose, glucose, ribose and rhamnose. The predominant menaquinones were MK-9(H4) and MK-10(H2). The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol and ninhydrin-positive phosphoglycolipids. The major fatty acid was iso-C(16 : 0). The G+C content of the genomic DNA was 68.2 mol%. On the basis of 16S rRNA gene sequence, the strain was shown to be most closely related to species of the genus Actinophytocola. DNA-DNA hybridization relatedness values (<70%) of the isolate with its closest neighbour Actinophytocola xinjiangensis QAIII60(T) supported classification of the isolate as a representative of a novel species. On the basis of phylogenetic analysis, and phenotypic and genotypic data, it is concluded that the new isolate belongs to a novel species of the genus Actinophytocola, for which the name Actinophytocola sediminis sp. nov. (type strain YIM M13705(T) = DSM 45939(T) = BCRC 16956(T)) is proposed.

Mariniluteicoccus flavus gen. nov., sp. nov., a new member of the family Propionibacteriaceae, isolated from a deep-sea sediment

A Gram-staining-positive, aerobic, non-motile, irregular coccus, designated strain YIM M13146(T), was isolated from a sediment sample collected from the South China Sea at a depth of 2439 m, and its taxonomic position was determined by a polyphasic approach. Optimal growth of the strain was observed at 30 °C (range 5-40 °C), pH 7.0 (pH 6.0-9.0) and 0-1% NaCl (0-6%, w/v) on/in tryptic soy agar/broth. Strain YIM M13146(T) had the major cellular fatty acid anteiso-C15:0, the predominant respiratory menaquinone MK-9(H4), peptidoglycan type A3γ (ll-DAP-Gly) containing alanine, glycine, glutamic acid and ll-diaminopimelic acid (ll-DAP) and the polar lipids phosphatidylcholine, diphosphatidylglycerol, one unknown phospholipid and several glycolipids. The G+C content of the DNA was 67.2 mol%. Phenotypic and chemotaxonomic characteristics together with 16S rRNA gene sequence analyses showed that strain YIM M13146(T) was distinct from its close phylogenetic relatives in the genera Propioniferax and Granulicoccus of the family Propionibacteriaceae. Hence, a new genus and species, Mariniluteicoccus flavus gen. nov., sp. nov., is proposed. The type strain of Mariniluteicoccus flavus is YIM M13146(T) ( = DSM 25892(T) = CCTCC AB 2012055(T)).

Marininema halotolerans sp. nov., a novel thermoactinomycete isolated from a sediment sample, and emended description of the genus Marininema Li et al. 2012

A novel Gram-stain-positive bacterium, designated strain YIM M11385(T), was isolated from a marine sediment sample collected from the South Bay, Little Andaman Island, India with a salinity of 35 p.p.m., pH 8.5. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM M11385(T) belongs to the genus Marininema, supported by a bootstrap value of 100 %. The taxonomic position of this organism was further established by using a polyphasic approach. Strain YIM M11385(T) grew optimally at 28 °C, pH 7.0 and in the presence of 0-5 % (w/v) NaCl. The 16S rRNA gene sequence similarity between strain YIM M11385(T) and Marininema mesophilum SCSIO 10219(T) was 98.3 %. Strain YIM M11385(T) exhibited a quinone system with only MK-7, the polar lipid profile included diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine as major components, and the major fatty acids were anteiso-C15 : 0, iso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The level of DNA-DNA relatedness between strain YIM M11385(T) and M. mesophilum SCSIO 10219(T) was 59.36 %. On the basis of genotypic and phenotypic data, it is apparent that strain YIM M11385(T) represents a novel species of the genus Marininema, for which the name Marininema halotolerans sp. nov. is proposed. The type strain is YIM M11385(T) ( = CCTCC AB 2012052(T) = DSM 45789(T)). In addition, we propose that the description of the genus Marininema should be further emended based on the results of the present study.