[Study of mycelial polysaccharide from Paraisaria dubia of Ophiocordyceps gracilis asexual].

In order to provide a foundation for the development and application of Ophiocordyceps gracilis and increase the new resources of cordyceps,an asexual Paraisaria dubia was isolated from an O. gracilis fruit body. After 10 days of liquid fermentation,white globular mycelium and clear transparent fermentation were produced. The mycelium was extracted by hot water and precipitated with ethanol to obtain intracellular crude polysaccharide. The protein was deproteinized to obtain deproteinized polysaccharide. The intracellular pure polysaccharide was purified by Sepharose 4 B column chromatography and were analyzed by UV,IR,1 H-NMR,and13 CNMR data,as well as GC and HPLC. The results showed that the intracellular polysaccharide of P. dubia was composed of glucose,galactose and mannose with a molar ratio of 25. 54 ∶2 ∶1. It was a ß-configuration glycosylic bond,containing pyranoside. The initial connection of polysaccharide was ß(1→2)(1→4)(1→6) connection. This experiment provides a theoretical basis for the development and application of P. dubia.

[Identification and antibacterial effect research of a Tolypocladium strain isolated from sclerotium of Ophiocordyceps gracilis in Xinjiang].

OBJECTIVE: To promote development and utilization of Ophiocordyceps gracilis in xinjiang and provide basic data for researching and sustainable developing medicine fungus related to O. gracilis. METHOD: A white strain SFYT002 isolated from the sclerotium of O. gracilis in Xinjiang was researched by morphological observation, ITS and 18SrDNA sequencing. The ITS and 18SrDNA sequences of the strain were determined, BLAST was compared with the other sequences of Tolypocladium in GenBank. The phylogenetic trees of ITS and 18SrDNA sequences were analyzed in Tolypocladium. In addition, the filter paper method was used to study the antibacterial effects. RESULT: The main morphological characters of this strain were white cotton-like colonies, phialide with inflated base, drastically sharping with partially bending tips, small and transparent budding spores with being always assemble to spearhead and globular, subglobular or ellipse conidiospores. The phylogenetic trees of ITS and 18SrDNA sequences were constructed and analyzed in Tolypocladium. It was resulted that Tolypocladium was confirmed to be monophyletic, and the strain SFYT002 was the same as the systematic position of others of T. inflatum. Meanwhile, the antibacterial test was performed against the 4 common pathogenic bacteria. It was showed that both fermentation and its extracts of different polar from this strain possessed good anti-bacteria capacities. CONCLUSION: The strain SFYT02 was identified as T. inflatum, and inhibited effectively growth of bacteria.

The complete mitochondrial genome of Ophiocordyceps gracilis and its comparison with related species.

In this study, the complete mitochondrial genome of O. gracilis was sequenced and assembled before being compared with related species. As the second largest mitogenome reported in the family Ophiocordycipitaceae, the mitogenome of O. gracilis (voucher OG201301) is a circular DNA molecule of 134,288 bp that contains numerous introns and longer intergenomic regions. UCA was detected as anticodon in tRNA-Sec of O. gracilis, while comparative mitogenome analysis of nine Ophiocordycipitaceae fungi indicated that the order and contents of PCGs and rRNA genes were considerably conserved and could descend from a common ancestor in Ophiocordycipitaceae. In addition, the expansion of mitochondrial organization, introns, gene length, and order of O. gracilis were determined to be similar to those of O. sinensis, which indicated common mechanisms underlying adaptive evolution in O. gracilis and O. sinensis. Based on the mitochondrial gene dataset (15 PCGs and 2 RNA genes), a close genetic relationship between O. gracilis and O. sinensis was revealed through phylogenetic analysis. This study is the first to investigate the molecular evolution, phylogenetic pattern, and genetic structure characteristics of mitogenome in O. gracilis. Based on the obtained results, the mitogenome of O. gracilis can increase understanding of the genetic diversity and evolution of cordycipitoid fungi.

Altered profiles of fecal bile acids correlate with gut microbiota and inflammatory responses in patients with ulcerative colitis.

BACKGROUND: Gut microbiota and its metabolites may be involved in the pathogenesis of inflammatory bowel disease. Several clinical studies have recently shown that patients with ulcerative colitis (UC) have altered profiles of fecal bile acids (BAs). It was observed that BA receptors Takeda G-protein-coupled receptor 5 (TGR5) and vitamin D receptor (VDR) participate in intestinal inflammatory responses by regulating NF-ĸB signaling. We hypothesized that altered profiles of fecal BAs might be correlated with gut microbiota and inflammatory responses in patients with UC. AIM: To investigate the changes in fecal BAs and analyze the relationship of BAs with gut microbiota and inflammation in patients with UC. METHODS: The present study used 16S rDNA sequencing technology to detect the differences in the intestinal flora between UC patients and healthy controls (HCs). Fecal BAs were measured by targeted metabolomics approaches. Mucosal TGR5 and VDR expression was analyzed using immunohistochemistry, and serum inflammatory cytokine levels were detected by ELISA. RESULTS: Thirty-two UC patients and twenty-three HCs were enrolled in this study. It was found that the diversity of gut microbiota in UC patients was reduced compared with that in HCs. Firmicutes, Clostridium IV, Butyricicoccus, Clostridium XlVa, Faecalibacterium, and Roseburia were significantly decreased in patients with UC (P = 3.75E-05, P = 8.28E-07, P = 0.0002, P = 0.003, P = 0.0003, and P = 0.0004, respectively). Proteobacteria, Escherichia, Enterococcus, Klebsiella, and Streptococcus were significantly enriched in the UC group (P = 2.99E-09, P = 3.63E-05, P = 8.59E-05, P = 0.003, and P = 0.016, respectively). The concentrations of fecal secondary BAs, such as lithocholic acid, deoxycholic acid, glycodeoxycholic acid, glycolithocholic acid, and taurolithocholate, in UC patients were significantly lower than those in HCs (P = 8.1E-08, P = 1.2E-07, P = 3.5E-04, P = 1.9E-03, and P = 1.8E-02, respectively) and were positively correlated with Butyricicoccus, Roseburia, Clostridium IV, Faecalibacterium, and Clostridium XlVb (P < 0.01). The concentrations of primary BAs, such as taurocholic acid, cholic acid, taurochenodeoxycholate, and glycochenodeoxycholate, in UC patients were significantly higher than those in HCs (P = 5.3E-03, P = 4E-02, P = 0.042, and P = 0.045, respectively) and were positively related to Enterococcus, Klebsiella, Streptococcus, Lactobacillus, and pro-inflammatory cytokines (P < 0.01). The expression of TGR5 was significantly elevated in UC patients (0.019 ± 0.013 vs 0.006 ± 0.003, P = 0.0003). VDR expression in colonic mucosal specimens was significantly decreased in UC patients (0.011 ± 0.007 vs 0.016 ± 0.004, P = 0.033). CONCLUSION: Fecal BA profiles are closely related to the gut microbiota and serum inflammatory cytokines. Dysregulation of the gut microbiota and altered constitution of fecal BAs may participate in regulating inflammatory responses via the BA receptors TGR5 and VDR.