Yu-Zhen Wei

Saccharopolyspora antimicrobica sp. nov., an actinomycete from soil

Three Gram-positive, aerobic, non-motile, non-acid-alcohol-fast strains, designated I05-00051, I05-00074T and I03-00808, were isolated from different soil samples in Beijing and Sichuan, China. Phylogenetic analysis based on 16S rRNA gene sequences and DNA-DNA hybridization experiments revealed that these three isolates represented the same genospecies. These three strains showed <97.0 % 16S rRNA gene sequence similarity with the type strains of recognized species of the genus Saccharopolyspora, with the exception of Saccharopolyspora hirsuta subsp. hirsuta DSM 43463T (98.1 % gene sequence similarity) and Saccharopolyspora spinosa DSM 44228T (98.0 % similarity). Chemotaxonomic data, including meso-diaminopimelic acid as the diagnostic diamino acid, arabinose and galactose as predominant sugars, iso-C15 : 0, iso-C16 : 0, iso-C17 : 0 and anteiso-C17 : 0 as major fatty acids, MK-9(H4) as predominant menaquinone and polar lipids dominated by diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol and phosphatidylinositol, supported the affiliation of these three organisms to the genus Saccharopolyspora. The genomic DNA G+C contents of the three isolates were 68.2-69.9 mol%. The results of DNA-DNA hybridization experiments among these three isolates and S. hirsuta subsp. hirsuta DSM 43463T and S. spinosa DSM 44228T, in combination with chemotaxonomic and physiological data, demonstrated that the three new isolates represent a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora antimicrobica sp. nov. is proposed. The type strain is I05-00074T (=CCM 7463T=KCTC 19303T).

Antimycin A 18 produced by an endophytic Streptomyces albidoflavus isolated from a mangrove plant

Antimycin A 18 produced by an endophytic Streptomyces albidoflavus isolated from a mangrove plant

Allonocardiopsis opalescens gen. nov., sp. nov., a new member of the suborder Streptosporangineae, from the surface-sterilized fruit of a medicinal plant.

An endophytic actinomycete, designated strain I10A-01259(T), was isolated from a surface-sterilized fruit of Lonicera maackii (Rupr.) Maxim., a medicinal plant, which was collected from a suburb of Beijing, China. Whole-cell hydrolysates of the isolate contained galactose and meso-diaminopimelic acid. The predominant phospholipids were phosphatidylglycerol and diphosphatidylglycerol; the menaquinones consisted mainly of MK-9, MK-11 and MK-12, with a minor amount of MK-10. The major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and iso-C15 : 0. Comparative analysis of 16S rRNA gene sequences indicated that strain I10A-01259(T) was most closely related to Nocardiopsis arabia S186(T) (93.2 % sequence similarity), Thermobifida halotolerans YIM 90462(T) (93.0 %) and other strains of genera within the families Nocardiopsaceae and Thermomonosporaceae. On the phylogenetic tree based on 16S rRNA gene sequences, strain I10A-01259(T) fell within the radius of the suborder Streptosporangineae, in which the strain formed a distinct lineage next to the genera of the families Nocardiopsaceae and Thermomonosporaceae. Based on the data from our polyphasic taxonomic study, a novel genus and species, Allonocardiopsis opalescens gen. nov., sp. nov., are proposed within the suborder Streptosporangineae. The type strain of Allonocardiopsis opalescens is strain I10A-01259(T) ( = CPCC 203428(T)  = DSM 45601(T)  = KCTC 19844(T)).

Nocardioides perillae sp. nov., isolated from surface-sterilized roots of Perilla frutescens

A Gram-stain-positive, rod-shaped actinobacterium, designated strain I10A-01402(T), was isolated from surface-sterilized roots of a medicinal plant, Perilla frutescens, collected in a suburb of Beijing, China. Chemotaxonomically, the strain contained ll-diaminopimelic acid as the diagnostic diamino acid and MK-8(H4) as the predominant menaquinone. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The major fatty acids were C17 : 1ω9c, C18 : 1ω9c, C17 : 0, C16 : 0 and iso-C16 : 0. The genomic DNA G+C content was 70.4 mol%. 16S rRNA gene sequence analysis indicated that strain I10A-01402(T) belonged to the genus Nocardioides. Phylogenetic analyses based on 16S rRNA gene sequences showed that the isolate formed a robust cluster with Nocardioides ginsengisegetis Gsoil 485(T), N. koreensis MSL-09(T) and N. alkalitolerans KSL-1(T). On the basis of the evidence from our polyphasic taxonomic study, a novel species, Nocardioides perillae sp. nov., is proposed. The type strain is I10A-01402(T) ( = CPCC 203382(T)  = DSM 24552(T)  = KCTC 29022(T)).

Actinopolymorpha cephalotaxi sp. nov., a novel actinomycete isolated from rhizosphere soil of the plant Cephalotaxus fortunei

An actinomycete, strain I06-2230(T), was isolated from rhizosphere soil of the plant Cephalotaxus fortunei, collected from Yunnan province, south China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Actinopolymorpha. Cells grew on agar surfaces, with no penetration even after prolonged cultivation. Aerial hyphae were absent. Cells were irregularly shaped and remained attached as chains or aggregates. Chemotaxonomic data, which showed ll-diaminopimelic acid in the cell wall, glucose as the whole-cell sugar, type PI phospholipids and MK-9(H4) as the predominant menaquinone, supported the affiliation of strain I06-2230(T) to the genus Actinopolymorpha. The major fatty acids were iso-C(15 : 0), iso-C(16 : 0) and iso-C(16 : 1) H. The genomic DNA G+C content was 69.3 mol%. DNA-DNA hybridization data, in combination with chemotaxonomic, physiological and biochemical data, demonstrated that strain I06-2230(T) should be classified as representing a novel species of the genus Actinopolymorpha. The name Actinopolymorpha cephalotaxi sp. nov. is proposed, with strain I06-2230(T) (=DSM 45117(T)=CCM 7466(T)=KCTC 19293(T)) as the type strain.

Molecular analysis of fungal diversity associated with three bryophyte species in the Fildes Region, King George Island, maritime Antarctica

The fungal communities associated with three bryophytes species (the liverwort Barbilophozia hatcheri, the mosses Chorisodontium aciphyllum and Sanionia uncinata) in the Fildes Region, King George Island, maritime Antarctica, were studied using clone library analysis. Fungal communities showed low diversity; the 680 clones belonged to 93 OTUs. Of these, 78 belonged to the phylum Ascomycota, 13 to the phylum Basidiomycota, 1 to the phylum Zygomycota, and 1 to an unknown phylum. Among the OTUs, the most common orders in the Ascomycota were Helotiales (42 OTUs) and Chaetothyriales (14 OTUs) and the most common orders in the Basidiomycota were Sebacinales (3 OTUs) and Platygloeales (3 OTUs). Most OTUs clustered within clades that contained phylotypes identified from samples in Antarctic or Arctic ecosystems or from bryophytes in other ecosystems. In addition, we found that host-related factor may shape the fungal communities associated with bryophytes in this region. This is the first systematic study of the fungal community in Antarctic bryophytes to be performed using culture-independent method and the results may improve understanding of the endophytic fungal evolution and ecology in the Antarctic ecosystem.

Agromyces flavus sp. nov., an actinomycete isolated from soil

A gram-positive, non-motile strain, designated CPCC 202695(T), was isolated from a soil sample collected from the Qinghai-Tibet plateau, north-west China. Strain CPCC 202695(T) contained rhamnose, glucose and galactose in the cell wall as diagnostic sugars and 2,4-diaminobutyric acid, alanine, glutamic acid and glycine in the peptidoglycan. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. MK-12 was the predominant menaquinone and anteiso-C(15 : 0) (34.2 %), iso-C(15 : 0) (19.8 %), iso-C(16 : 0) (12.7 %) and anteiso-C(17 : 0) (11.1 %) were the major fatty acids. 16S rRNA gene sequence similarities (94.2-97.1 %) between the isolate and the type strains of recognized species of the genus Agromyces indicated that strain CPCC 202695(T) was a member of the genus Agromyces. DNA-DNA relatedness clearly separated strain CPCC 202695(T) from its closest relatives. The phenotypic and genotypic data demonstrated that strain CPCC 202695(T) represents a novel species of the genus Agromyces, for which the name Agromyces flavus sp. nov. is proposed. The type strain is CPCC 202695(T) ( = KCTC 19578(T)  = CCM 7623(T)).

Williamsia sterculiae sp. nov., isolated from a Chinese medicinal plant.

Two actinobacterial strains, CPCC 203464(T) and CPCC 203448, isolated from surface-sterilized stems of medicinal plants were subjected to a polyphasic taxonomic study. These two aerobic organisms formed pale yellow colonies on tryptic soy agar (TSA). Cells were Gram-stain-positive, non-acid-fast, non-motile, rod- or coccoid-like elements. Comparative 16S rRNA gene sequence analysis indicated that strains CPCC 203464(T) and CPCC 203448 were most closely related to the type strains of the species of the genus Williamsia. Chemotaxonomic properties such as containing meso-diaminopimelic acid in the cell wall, arabinose, galactose and ribose being the whole-cell hydrolysate sugars, phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and phosphatidylinositol (PI) as the phospholipids, and C16 : 0, 10-methyl C18 : 0, C18 : 1ω9c, C16 : 1ω7c and/or iso-C15 : 0 2-OH as major fatty acids supported the affiliation of strains CPCC 203464(T) and CPCC 203448 to the genus Williamsia. The DNA-DNA hybridization values in combination with differentiating chemotaxonomic and physiological characteristics strongly suggested that these two isolates should be classified as representatives of a novel species of the genus Williamsia. The name Williamsia sterculiae sp. nov. is proposed, with strain CPCC 203464(T) ( = DSM 45741(T) = KCTC 29118(T)) as the type strain.

Mycophenolic acid induces ATP-binding cassette transporter A1 (ABCA1) expression through the PPARγ-LXRα-ABCA1 pathway.

ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I and plays an important role in atherosclerosis. In a previous study, we developed a high-throughput screening method using an ABCA1p-LUC HepG2 cell line to find upregulators of ABCA1. Using this method in the present study, we found that mycophenolic acid (MPA) upregulated ABCA1 expression (EC50=0.09 μM). MPA upregulation of ABCA1 expression was confirmed by real-time quantitative reverse transcription-PCR and Western blot analysis in HepG2 cells. Previous work has indicated that MPA is a potent agonist of peroxisome proliferator-activated receptor gamma (PPARγ; EC50=5.2-9.3 μM). Liver X receptor α (LXRα) is a target gene of PPARγ and may directly regulate ABCA1 expression. Western blot analysis showed that MPA induced LXRα protein expression in HepG2 cells. Addition of PPARγ antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXRα protein expression. These data suggest that MPA increased ABCA1 expression mainly through activation of PPARγ. Thus, the effects of MPA on upregulation of ABCA1 expression were due mainly to activation of the PPARγ-LXRα-ABCA1 signaling pathway. This is the first report that the antiatherosclerosis activity of MPA is due to this mechanism.

Tenggerimyces mesophilus gen. nov., sp. nov., a member of the family Nocardioidaceae.

A novel aerobic actinomycete, designated strain I12A-02601T, was isolated from a desert soil crusts sample collected from the Shapotou region of Tengger Desert, north-west China. The substrate mycelia of this isolate were well-developed and branched, but not fragmented. The maturity aerial mycelia formed short chains of small, rod-shaped spores. The strain contained ll-diaminopimelic acid, dd-diaminopimelic acid, galactose, glucose, ribose and xylose in its whole-cell hydrolysates. The polar lipids consisted of diphosphatidylglycerol, N-acetylglucosamine-containing phospholipids, phosphatidylinositolmannoside and glycolipids. The predominant menaquinones were MK-10(H6) and MK-10(H8). The major fatty acids were iso-C15 : 0, anteiso-C15 : 0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0. The G+C content of the genomic DNA was 72.2 mol%. The 16S rRNA gene sequences comparison showed that strain I12A-02601T was most closely related to members of the family Nocardioidaceae, such as Actinopolymorpha alba YIM 48868T (93.3 % sequence similarity), Actinopolymorpha pittospori PIP 143T (93.2 %), and Flindersiella endophytica EUM 378T (93.2 %). In the phylogenetic tree based on 16S rRNA gene sequences, strain I12A-02601T formed a clade with the members of the genera Flindersiella, Thermasporomyces, and Actinopolymorpha in the family Nocardioidaceae. Combined data from this taxonomic study using a polyphasic approach, led to the conclusion that strain I12A-02601T represents a novel species of a new genus in the family Nocardioidaceae, for which the name Tenggerimyces mesophilus gen. nov., sp. nov. is proposed. The type strain of the type species is I12A-02601T ( = CPCC 203544T = DSM 45829T = NBRC 109454T).