Phytohabitans maris sp. nov., isolated from marine sediment.

A novel actinobacterium, strain ZYX-F-186T, was isolated from marine sediment sampled on Yongxing Island, Hainan Province, PR China. Based on the results of 16S rRNA gene sequence analysis, strain ZYX-F-186T belongs to the genus Phytohabitans, with high similarity to Phytohabitans kaempferiae KK1-3T (98.3 %), Phytohabitans rumicis K11-0047T (98.1 %), Phytohabitans flavus K09-0627T (98.1 %), Phytohabitans houttuyneae K11-0057T (97.9 %), Phytohabitans suffuscus K07-0523T (97.7 %), and Phytohabitans aurantiacus RD004123T (97.7 %). Phylogenetic analysis of 16S rRNA gene sequences showed that the strain formed a single subclade in the genus Phytohabitans. The novel isolate contained meso-diaminopimelic acid, d-glutamic acid, glycine, d-alanine, and l-lysine in the cell wall. The whole-cell sugars were xylose, arabinose, ribose, and rhamnose. The predominant menaquinones were MK-9(H8), MK-9(H6), and MK-9(H4). The characteristic phospholipids were phosphatidylethanolamine, phosphatidylinositol, phosphatidylmethylethanolamine, phosphatidylglycerol, and an unknown phospholipid. The major fatty acids (>5 %) were iso-C16 : 0, anteiso-C17 : 0, and iso-C18 : 0. Genome sequencing showed a DNA G+C content of 71.9 mol%. Low average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values demonstrated that strain ZYX-F-186T could be readily distinguished from its closely related species. Based on its phylogenetic, chemotaxonomic, and physiological characteristics, strain ZYX-F-186T represents a novel species of the genus Phytohabitans, for which the name Phytohabitans maris sp. nov. is proposed. The type strain is ZYX-F-186T (=CGMCC 4.8025T=CCTCC AA 2023025T=JCM 36507T).

Diverse ansamycin derivatives from the marine-derived Streptomyces sp. ZYX-F-97 and their antibacterial activities.

Four new ansamycin derivatives, named 1,19-epithio-geldanamycin A (1), 17-demethoxylherbimycin H (2), herbimycin M (3), and seco-geldanamycin B (4), together with eight known ansamycin analogues (5-12) were isolated from the solid fermentation of marine-derived actinomycete Streptomyces sp. ZYX-F-97. The structures of new compounds were elucidated by extensive spectroscopic analysis as well as nuclear magnetic resonance (NMR) and electronic circular dichroism (ECD) calculations. All the compounds were assayed for their antibacterial activity. Among them, compounds 4, 8, and 12 exhibited remarkable inhibition against Listeria monocytogenes with minimum inhibitory concentrations (MIC) values ranging from 8 µg·mL-1 to 64 µg·mL-1, and displayed moderate inhibition against methicillin-resistant Staphylococcus aureus (MRSA) with MIC value of 64 µg·mL-1. Compounds 4, 8, 9, and 12 showed moderate inhibition activities against both Staphylococcus aureus and Bacillus subtilis with MIC values ranging from 32 µg·mL-1 to 128 µg·mL-1.

Two new species of Cladosporium from leaf spots of Parispolyphylla in north-western Yunnan Province, China.

BACKGROUND: During the survey of pathogenic fungi on medicinal plant leaves in Yunnan Province, China, two Cladosporium-like taxa were isolated from leaf spots of Parispolyphylla. Based on morphological characteristics and phylogenetic analysis of combined ITS, TEF1-α and ACT genes, two new species were discovered. NEW INFORMATION: Two new species Cladosporiumyunnanensis and C.paris are introduced, the detailed descriptions and illustrations are provided. Morphology of the two new species is compared with other related Cladosporium species. This study widens the host diversity of the genus Cladosporium.

[Research advances on resource and biological control of endoparasitic fungi.] / çº¿è™«å† å¯„ç”ŸçœŸèŒèµ„æºåŠç”Ÿé˜²åº”ç”¨ç ”ç©¶è¿›å±•.

Endoparasitic fungi are a group of nematophagous fungi which produce a variety of special spores to infect free nematodes. They play a key role in maintaining the population density of nematodes in the natural systems. Moreover, they are important materials for the study of species diversity. Therefore, they have special research significance and economic values. At present, many studies mainly focus on the infectivity of trapping fungi to nematodes, and mainly directed at the second instars larvae. However, the endoparasitic fungi have infectivity to nematodes at all stages. Here, we reviewed the resource status, diversity of spore morphology, infection modes, life history and host of endoparasitic fungi, and the biocontrol fungi with development potential and their commercialized application. Finally, we proposed some suggestions for future researches.

GIT2 deficiency attenuates concanavalin A-induced hepatitis in mice.

G protein-coupled receptor kinase interactor 2 (GIT2) is a signaling scaffold protein involved in regulation of cytoskeletal dynamics and the internalization of G protein-coupled receptors (GPCRs). The short-splice form of GIT2 is expressed in peripheral T cells and thymocytes. However, the functions of GIT2 in T cells have not yet been determined. We show that treatment with Con A in a model of polyclonal T-lymphocyte activation resulted in marked inhibitions in the intrahepatic infiltration of inflammatory cells, cytokine response and acute liver failure in Git2 (-/-) mice. CD4(+) T cells from Git2 (-/-) mice showed significant impairment in proliferation, cytokine production and signal transduction upon TCR-stimulated activation. Our results suggested that GIT2 plays an important role in T-cell function in vivo and in vitro.

[Phylogenic diversity of soil chemotatic bacteria in a phosphorous-rich area around Dianchi Lake of Yunnan Province, Southwest China].

Phosphate-solubilizing bacteria (PSB) were isolated from 100 soil samples collected from a phosphorous-rich area around the Dianchi Lake of Yunnan Province, Southwest China. The chemotatic PSB strains were screened by cheA gene detection, and their chemotaxis was verified by the method of soft agar plate. The tricalcium phosphate (TCP)-solubilizing activities of PSB were determined with molybdenum blue spectrophotometry. Based on 16S rRNA sequences, the phylogenic relationships of the PSB were analyzed. A total of 145 PSB strains with a diameter of phosphate-solubilizing halo zone ranged from 0.5 cm to 2 cm were isolated, among which, 37 strains were chemotactic. The 37 chemotactic strains showed chemotaxis towards four test attractants, and exhibited TCP-solubilizing activity. Phylogenic analysis revealed that the 37 chemotatic strains were belonged to 17 species of 10 genera, in which, Pseudomonas was dominant (9 strains of 5 species), followed by Enterobacter (8 strains of 3 species). Only one species (Bacillus aryabhattai) was isolated from Bacillus, but 9 strains were identified.

[Phylogenetic diversity characteristics of soil bacteria producing nematode-attracting volatiles and identification of their active compounds].

OBJECTIVE: This study characterized the phylogenetic diversity of soil bacteria producing nematode-attracting volatiles and their nematode-attracting compounds. Results would enhance our understanding on the interaction between nematodes and soil microorganisms and potentially enhance the biocontrol efficiency when combined the attractants with nemacides. METHODS: Bacteria producing volatiles with functions of nematode-attracting activities were isolated from 187 agricultural soil samples collected in 26 provinces of China with the method of double-Petri dishes. The phylogenetic diversity of these bacteria was characterized by RFLP-16S rRNA gene sequence analysis. The nematode-attracting volatiles of bacteria were detected using the SPME-GC/MS, and volatile compounds with attractive activity were determined by confirming with individual commercial compounds. RESULTS: Among the 3800 bacteria isolated from the 187 soil samples, 196 isolates(5.16% of the total) showed attractive activity (AN)more than 30% to Panagrellus redivivus. Of the 196 isolates, 66 (1.74%) showed AN > or = 70%, 62 isolates (1.63%) showed AN between 50% and 70%, and 68 isolates (1.79%) showed AN less than 50%. Phylogenetic analysis revealed that the 196 bacteria were clustered into 5 groups: Bacilli, Gammaproteobacteria, Alphaproteobacteria, Sphingobacteria and Actinobacteria. But, Bacillus were the dominant, which covered 13 species. And 11 volatiles with nematode-attracting activity were determined, including benzaldehyde, 2-heptanone, benzyl benzoate, ethyl palmitate, (+)-longifolene, benzyl alcohol, p-anisaldehyde, vanatone, ethyl butyrate, isovanilin and d-alaninol. CONCLUSION: Some species of bacteria in agriculture soil can produce volatiles to attract nematodes.

The ecology of nematode-trapping hyphomycetes in cattle dung from three plateau pastures.

This paper investigated the influence of season and altitude on the occurrence of nematode-trapping fungi in cattle faeces. Six hundred and sixty samples of cattle faeces deposited on three plateau pastures with different altitudes in the west of Yunnan Province, China, were examined in 2004. A total of 17 species of nematode-trapping hyphomycetes were isolated from these samples. The predominant species from all three plateau pastures were Arthrobotrys oligospora, A. musiformis, Monacrosporium ellipsosporum, and M. thaumasium. Species with adhesive networks were the most frequently isolated. Overall, species diversity index was negatively correlated with altitude and was different among seasons within the same site. Levels of diversity were highest in the summer, followed by autumn, spring, and winter. The conidia of the hyphomycetes isolated here germinated normally on medium containing cattle faeces, with species developing adhesive networks having the highest rate of germination. However, the rate of conidial trap (CT) formation was lower in species with adhesive networks than those in other species.