Qin-Yuan Li

Fodinicurvata sediminis gen. nov., sp. nov. and Fodinicurvata fenggangensis sp. nov., poly-β-hydroxybutyrate-producing bacteria in the family Rhodospirillaceae

Two Gram-negatively stained, facultatively anaerobic, non-motile, vibrioid and rod-shaped, chemoheterotrophic bacterial strains, designated YIM D82(T) and YIM D812(T), were isolated from a salt mine in Yunnan, south-west China. DNA-DNA hybridization, genomic DNA G+C content and phylogenetic analyses based on 16S rRNA gene sequences divided the two isolates into two distinct genospecies that were also clearly differentiated by fatty acid profiles, carbon source utilization patterns, antibiotic susceptibility and biochemical characteristics. The two isolates grew in the presence of 1.5-20 % NaCl, and optimally at 28 degrees C and pH 7.5. The genomic DNA G+C contents of strains YIM D82(T) and YIM D812(T) were 61.5 and 62.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains YIM D82(T) and YIM D812(T) were members of the family Rhodospirillaceae and showed 90.5-90.6 % and 90.1-90.2 % similarities with their closest relatives, Rhodovibrio sodomensis and Rhodovibrio salinarum, respectively. Differential phenotypic and genotypic characteristics of the two isolates from recognized genera showed that the two strains should be classified as representing a new genus and two novel species for which the names Fodinicurvata sediminis gen. nov., sp. nov. (type strain YIM D82(T)=DSM 21159(T)=KCTC 22351(T)) and Fodinicurvata fenggangensis sp. nov. (type strain YIM D812(T)=CCTCC AA 208037(T)=DSM 21160(T)) are proposed.

Salinicoccus albus sp. nov., a halophilic bacterium from a salt mine

A novel Gram-positive-staining, catalase- and oxidase-positive, non-motile, non-spore-forming coccus, designated YIM-Y21(T), was isolated from a salt mine in Yunnan, south-west China. The strain was moderately halophilic, facultatively alkaliphilic and obligately aerobic. Colonies were white. Growth occurred with 1.0-30.0 % NaCl (optimum, 10.0 % NaCl), at pH 6.0-10.0 (optimum, pH 8.5) and at 5-40 degrees C (optimum, 25 degrees C). The major amino acid constituents of the cell wall were glycine and lysine. The major cellular fatty acids were anteiso-C(15 : 0), anteiso-C(17 : 0) and iso-C(15 : 0). MK-6 was the predominant respiratory quinone, with MK-7 present in minor amounts. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and an unidentified phospholipid. The DNA G+C content was 46.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain YIM-Y21(T) was most closely related to the type strains of the nine recognized species of the genus Salinicoccus. The sequence similarities between the isolate and the type strains of members of this genus were in the range of 90.6-93.8 %, which indicated that strain YIM-Y21(T) is a representative of a novel species within the genus Salinicoccus. Together with the phenotypic characteristics and chemotaxonomic differences, these results support the proposal of a novel species of the genus Salinicoccus, Salinicoccus albus sp. nov., with YIM-Y21(T) (=CCTCC AA 207024(T) =DSM 19776(T) =KCTC 13192(T)) as the type strain.

Halopolyspora alba gen. nov., sp. nov., isolated from sediment.

A novel halophilic, filamentous actinomycete, designated strain AFM 10251(T), was isolated from a sediment sample collected from the Dead Sea, Israel. The isolate grew with 10-35% multi-salts, and did not grow without NaCl or MgCl2. The isolate formed a white aerial mycelium, and long chains of arthrospores with more than 10 spores per chain. The spores were spherical or oval with warty surfaces, and sterile mycelium was present between individual spores. The isolate contained meso-diaminopimelic acid and a small proportion of LL-diaminopimelic acid as cell-wall diamino acids, and galactose and arabinose as whole-cell sugars. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and three unknown phospholipids. Major fatty acids were iso-C(16 : 0), iso-C(17 : 0), iso-C(15 : 0) and anteiso-C(17 : 0). The DNA G+C content of strain AFM 10251(T) was 66.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM 10251(T) and the genus Actinopolyspora formed a distinct lineage. Analysis of the secondary structures of variable areas of the 16S rRNA gene showed that strain AFM 10251(T) was different from all recognized species of the genus Actinopolyspora and members of the family Pseudonocardiaceae. Analysis of the signature nucleotides of the 16S rRNA gene showed that strain AFM 10251(T) and Actinopolyspora halophila formed a single group, but with base pair differences at positions 127 : 234 and 183 : 194. On the basis of analysis of chemical and molecular characteristics, strain AFM 10251(T) is considered to represent a novel species of a new genus in the family Actinopolysporaceae, for which the name Halopolyspora alba gen. nov., sp. nov. is proposed. The type strain of Halopolyspora alba is AFM 10251(T) ( = DSM 45976(T) = CGMCC 4.7114(T)).

Saccharospirillum salsuginis sp. nov., a gammaproteobacterium from a subterranean brine

A novel Gram-negative, non-sporulating, moderately halophilic, facultatively alkaliphilic, catalase- and oxidase-positive, obligately aerobic bacterium, strain YIM-Y25(T), was isolated from a subterranean brine sample collected from a salt mine in Yunnan, south-west China. Cells were spirilla, motile by monopolar flagella, with meso-diaminopimelic acid in the cell-wall peptidoglycan. Growth occurred with 1-15 % (w/v) NaCl (optimum 5 %), at pH 6.0-10.0 (optimum pH 8.0) and at 15-50 degrees C (optimum 35-40 degrees C). Ubiquinone Q-8 was the predominant respiratory quinone. Polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmonomethylamine and an unidentified phospholipid. The major cellular fatty acids were C(18 : 1)omega7c, iso-C(16 : 0), C(16 : 0) and C(16 : 1). The genomic DNA G+C content was 58.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM-Y25(T) was most closely related to the type strain of the sole recognized species of the genus Saccharospirillum, Saccharospirillum impatiens EL-105(T) (sequence similarity 97.0 %), and these two strains formed a robust lineage in the phylogenetic tree. The level of DNA-DNA relatedness between them was 12.6 %. The combination of phylogenetic analysis, phenotypic differences, chemotaxonomic properties and DNA-DNA hybridization data supported the view that this strain represents a novel species of the genus Saccharospirillum, for which the name Saccharospirillum salsuginis sp. nov. is proposed, with YIM-Y25(T) (=CCTCC AA 207033(T) =KCTC 22169(T)) as the type strain.

Tessaracoccus rhinocerotis sp. nov., isolated from the faeces of Rhinoceros unicornis

A novel Gram-stain-positive, non-spore-forming, irregular rod-shaped, non-motile and facultatively anaerobic actinobacterium, designated strain YIM 101269T, was isolated from the faeces of Rhinoceros unicornis living in Yunnan Wild Animal Park, Yunnan province, south-west China. The isolate grew at 10-35 °C, at pH 6-12 and with 0-9 % (w/v) NaCl. The cell-wall peptidoglycan of the organism contained ll-diaminopimelic acid as the diagnostic diamino acid. The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, three unidentified polar lipids, one unidentified aminophospholipid and three unknown glycolipids. The major cellar fatty acid was anteiso-C15 : 0.MK-10(H4) was the predominant menaquinone. The DNA G+C content was 69.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain YIM 101269T belonged to the genus Tessaracoccus, closely related to Tessaracoccus flavescens DSM 18582T (97.4 % similarity). Based on the evidence from the present study, strain YIM 101269T is considered to represent a novel species of the genus Tessaracoccus, for which the name Tessaracoccus rhinocerotis sp. nov. is proposed. The type strain is YIM 101269T ( = DSM 27579T = CCTCC AB 2013217T).

Microbacterium faecale sp. nov., isolated from the faeces of Columba livia.

A novel, yellow, aerobic strain, YIM 101168T, isolated from the faeces of a dove (Columba livia), was studied to determine its taxonomic position. Cells were Gram-stain-positive, short rod-shaped, oxidase-negative, catalase-positive and non-motile. The strain could grow at 7-37 °C, at pH 6-10 and in the presence of 0-13 % (w/v) NaCl. The strain had a 16S rRNA gene sequence similarity and DNA-DNA hybridization relatedness value with Microbacteriumgubbeenense NCIMB 30129T of 97.8 % and 41.5±8.7 %, respectively. Ornithine was detected as the diagnostic amino acid in the hydrolysate of the cell wall. Whole-cell sugars were found to be galactose, glucose, rhamnose, mannose and ribose. Major fatty acids (>10 %) were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. Major menaquinones were identified as MK-10, MK-11 and MK-12. The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, glycolipids and four unidentified lipids. The phylogenetic analyses as well as the chemotaxonomic and phenotypic characteristics indicate that strain YIM 101168T represents a novel species of the genus Microbacterium; the name Microbacterium faecale sp. nov. is proposed for the novel species and the type strain is YIM 101168T (=DSM 27232T=KCTC 39554T=CGMCC 1.15152T).

Corynebacterium faecale sp. nov., isolated from the faeces of Assamese macaque

A Gram-stain-positive, facultatively anaerobic, short rod-shaped, oxidase-negative and non-motile novel strain, designated YIM 101505T, was isolated from the faeces of a primate, Assamese macaque, and was studied to determine its taxonomic position. The cell wall contained meso-diaminopimelic acid and short-chain mycolic acids. Whole cell sugars were mannose, galactose and arabinose as major components. The major fatty acids (>10 %) were C18 : 1ω9c, C16 : 0 and C17 : 1ω8c and the major menaquinone was MK-9(H2). The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, glycolipid and six unidentified lipids. The new isolate shared most of the typical chemotaxonomic characteristics of members of the genus Corynebacterium. The closest related species was Corynebacterium efficiens based on 16S rRNA gene (98.1 % similarity) and partial rpoB gene (91.4 % similarity) sequences. Similarities with other species of this genus were below 97 % based on the 16S rRNA gene. The DNA-DNA hybridization value between YIM 101505T and C. efficiens DSM 44549T was 47.7±3.6 %. Moreover, the physiological and biochemical characteristics of YIM 101505T and C. efficiens DSM 44549T were different. Thus, strain YIM 101505T is considered to represent a novel member of the genus Corynebacterium, for which the name Corynebacterium faecale sp. nov. is proposed. The type strain is YIM 101505T (=DSM 45971T=CCTCC AB 2013226T).

Kineococcus gypseus sp. nov., isolated from saline sediment.

A novel Gram-stain-positive, aerobic, motile, non-spore-forming coccus-shaped actinomycete, designated strain YIM 121300T, was isolated from alkaline sediment in Yuanjiang, Yunnan province, south-west China. Phylogenetic analyses based on the 16S rRNA gene sequence showed that strain YIM 121300T was affiliated to the genus Kineococcus, and was closely related to Kineococcus aurantiacus IFO 15268T (97.3 % similarity). 16S rRNA gene sequence similarity to other species of the genus Kineococcus was < 97 %. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The whole-cell sugars contained arabinose, galactose, glucose, mannose and ribose. The predominant menaquinone was MK-9(H2). Mycolic acids were not detected. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and an unknown phospholipid. The predominant fatty acids were anteiso-C15 : 0 and anteiso-C15 : 1 A. The G+C content of the genomic DNA was 75.1 mol%. DNA–DNA relatedness (55 ± 4 % to K. aurantiacus IFO 15268T) and differential phenotypic data demonstrated that strain YIM 121300T was distinguished from all related species of the genus Kineococcus. On the basis of data from the present polyphasic study, the organism should be assigned to a novel species of the genus Kineococcus, for which the name Kineococcus gypseus sp. nov. is proposed. The type strain is YIM 121300T ( = CCTCC AA 2013232T = DSM 27627T).

The Distal Gut Bacterial Community of Some Primates and Carnivora

Huge numbers of bacteria reside in the digestive tract of host and these microorganisms play a vital role in the host health, especially in the digestion of food and the development of immune system. Host phylogeny and diet, especially long-term diet, both have great influence on the gut bacterial community. Other aspects of host, such as gender, age, and the geography and weather they lived, are also correlated to their gut bacterial community. Feces are usually used for gut bacteria study and fecal bacteria can represent the distal gut bacteria. In order to determine the influence of the host phylogeny and diet on the composition of distal gut bacterial community and to interpret bacterial population and diversity in the intestinal of animals, the distal gut bacterial community of four kinds of primates and five kinds of carnivora (including herbivorous, omnivorous, and carnivorous) were investigated using high-throughput sequencing and the isolation of the Actinobacteria from fresh feces of several primates was processed. The results showed the host phylogeny had a greater influence on the distal gut bacterial community of the primates and carnivora than the host diet. A total of 44 bacteria phyla and two archaea phyla were detected, which indicated that the distal gut bacteria of these animals were abundant. The distal gut bacteria were relatively stable and wildly shared in primates and carnivora. The difference in distal gut bacteria of the two animal orders is mainly determined by relative abundance of most distal gut bacteria rather than by the taxa of these bacteria.

Structure determination of two new sesquiterpenoids from Streptomyces sanglieri.

Sesquiterpenoids are a group of abundant and structurally diverse secondary metabolites mainly derived from plant and fungi. By contrast, they are rarely isolated from bacteria, and the terpene synthase genes had been considered to be silent in prokaryotes. Recently, more and more terpenes were identified from bacteria, and the biosynthesis of some terpenes has been discussed in heterologous bacteria. Actually, it demonstrated that the terpene synthases are widely distributed in bacteria, including streptomycete, and some new sesquiterpenoids and diterpenoids had been obtained through heterologous expression of terpene synthase genes derived from Streptomyces microorganism. In our ongoing investigation of new bioactive natural products from streptomycete, two new sesquiterpenes, 15-hydroxy-(+)-epicubenol (1) and 7β-hydroxy-7-epi-α-eudesmol (2), were identified from a fermentation broth of Streptomyces sanglieri (YIM 121209-2), which was isolated from the forest soil sample collected from Wuyi Mountain, Fujian Province, China. The structures of compounds 1 and 2 (Fig. 1) were elucidated based on detailed spectroscopic data analyses, including 1D and 2D NMR techniques. The cytotoxicity against two human cancer cell lines and antimicrobial activity against a panel of bacteria and fungi of 1 and 2 were evaluated. None of them showed cytotoxic or antimicrobial activities at 100μg/ml.