Hygrophoropsis is a small genus in Hygrophoropsidaceae of Boletales. A new and edible species, H. phragmiticola, is described based on morphological characteristics, molecular evidence, ecology and geographic distribution. The new species is characterized by creamy-whitish to pale-ochraceous pileal surface, white to cream gills, oblong or ellipsoid, thick-walled, weakly dextrinoid basidiospores measuring 6-10×4-5.5 μm, and growing on Phragmites species in northern China. Molecular analysis based on ITS and nrLSU sequences demonstrates the phylogenetic position of the new species in Hygrophoropsis. The new species and its closely related species are compared and discussed.
The ‘reed mushrooms’ are general designation of wild edible fungi grown with Phragmites australis or Tamarix ramosissima in lakeside and mainly distributed in Xinjiang. In this study, ITS1-5.8S-ITS2 (ITS) sequences were used to assess species delimitation of the specimens of ‘reed mushroom’ collected from Xinjiang. Combined with morphological examination, four species of Agaricus, i.e. A. bitorquis, A. padanus, A. sinodeliciosus, and A. subperonatus were recognized. The morphological descriptions, photos, and ITS for each species, as well as the dichotomous key were given. Maximum likelihood phylogenetic analysis of 55 ITS sequences from GenBank and 91 newly generated sequences in this study were performed. The four species from Xinjiang were well supported in the ITS tree. Voucher specimens were deposited in the Mycological Herbarium, Institute of Microbiology, Chinese Academy of Sciences, Beijing (HMAS). The geographical distribution data and correlating environmental factors of A. sinodeliciosus were used to model potential distribution using the maximum entropy model (MaxEnt). The highly suitable growing regions of A. sinodeliciosus were relatively limited, mainly located in northwestern China and Central Asia. In China, it is mainly distributed in the two sides of Tianshan Mountains, southwestern Tibet, Haixi State of Qinghai, northwestern Gansu, and western Inner Mongolia. The most effective environmental factors, namely the precipitation of wettest month, the precipitation of warmest quarter, the mean temperature of coldest quarter and the maximum temperature of warmest month, had decisive influence upon distribution of the species. Due to limited suitable region of A. sinodeliciosus growth, the protection should be strengthened and sustainable utilization approaches should be developed.
The diversity and community structure of endophytic fungi in quinoa seeds from different areas in Tibet were explored for the purpose of providing the basis for utilization of microbial resources in biocontrol practice. The cultivable fungi in seeds of quinoa collected from three areas of Tibet with different altitudes were isolated using traditional methods. In total 947 fungal strains were isolated from 46 quinoa seed samples and they were identified as 77 species belonging to 26 genera, 12 families, 9 orders, 1 phylum by ITS sequence analysis and morphological observation. All the fungi belonged to Ascomycota, and the three most dominant genera were Alternaria (isolation frequency 40.2%), Fusarium (17.4%), and Phoma (13.9%). Diversity of endophytic culturable fungi in quinoa seeds in Shigatse region was significantly higher than that in Lhasa and Nyingchi regions.
Candida glabrata is the most frequently isolated pathogen of candidiasis in immunocompromised hosts next to C. albicans. It is survivable under a wide range of environmental conditions, and the ability to adapt to pH changes in the host niches is closely related to pathogenesis. This study found that alkaline pH conditions repressed cell proliferation of C. glabrata, and the key regulators Rim101, Rim8, and Rim21 were involved in this regulation. The TOR signaling pathway plays an important role in the control of pH-regulated cell proliferation. It was further found that alkaline pH also affected the cell wall integrity of C. glabrata. Facts draw the conclusion that the inhibitory effects of pH changes on cell growth and cell wall integrity could provide clues to the development of new strategies of the control of infections caused by C. glabrata.
Ocean is rich in animal, plant and microbial resources, among which marine fungi are an important component part. Our previous study found that Engyodontium album, a deep-sea-derived fungus, can produce a secondary metabolite engyodontiumin A which can inhibit the growth of Aspergillus niger, Staphylococcus aureus, and Vibrio vulnificus, and is a potential marine antibacterial drug. So far, the genetic transformation system of E. album has not been developed, which is disadvantageous to the research on the regulation mechanism of secondary metabolite biosynthesis and other functional genes. In this study, the protoplasts of E. album were prepared, PEG3350-mediated protoplast transformation system was developed, and pCT74-sGFP plasmid was successfully introduced into the protoplast of E. album. Results demonstrated that the exogenous GFP could be stably expressed. To investigate whether the gene deletion strategy could be applicable in E. album, EaSHO1, a homologous gene of the yeast high-osmolarity glycerol pathway related gene identified through homologous comparison of amino acid sequences, was selected for preliminary analysis. The knockout mutants of EaSHO1 gene were obtained by replacing the open reading frame (ORF) of target gene with the hygromycin phosphotransferase (HPH) gene using homologous recombination method, and verified by Southern blot. The phenotypes caused by EaSHO1 deletion were further analyzed. The results showed that the deletion of EaSHO1 did not affect the vegetative growth and response against high salinity stress in E. album. Subcellular localization analysis showed that EaSho1-GFP mainly localized on the hyphal septa. In summary, the genetic transformation system of a deep-sea-derived E. album strain was successfully developed, and the biological function of its gene EaSHO1 was preliminarily analyzed.
Cyniclomyces guttulatus is a common inhabitant of the gastrointestinal tract of animals such as dogs, rabbits, guinea pigs, chinchillas, rats and mice. Compared with most common yeasts, C. guttulatus has unique adaptive characteristic to high concentration of acid (pH 1.5-4.5) and high temperature (38-42 °C) and could proliferate rapidly in vitro. A large number of C. guttulatus was found in diarrhea animals. Although there was no direct evidence, the infection of C. guttulatus could lead to obvious diseases. Thus, this yeast may be considered as an opportunistic pathogen of a large number of animals. The objective of this study was to obtain a systematic genome and transcriptome data of C. guttulatus. The genes structure and annotation of C. guttulatus were obtained by the whole genome and transcriptome sequencing. It was confirmed that this yeast genome has a size of 29.71 Mb containing 11 307 genes and the size of the transcriptome was 17.67 Mb; the GC content was 43.02% and 43.09%, respectively. The average length of mRNA, CDS, exons and introns were 1 476, 1 447, 1 374 and 540 bp respectively. In total, 517 unique gene families including 1 162 genes were found in C. guttulatus. The results revealed that the genome size and the gene number of C. guttulatus are obviously larger than those of other 12 yeast species. A whole genome duplication even may have occurred in this species, which could explain its unique characteristics of colonization in the gastrointestinal tract and unique resistance to high concentration of acid and high temperature.
Verticillium dahliae can infect more than 660 species of host plants such as cotton, potato and tomato, causing Verticillium wilt and serious economic losses. In order to understand the pathogenic mechanism of V. dahliae, the up-regulated differentially expressed gene encoding mitochondrial glycerol-3-phosphate dehydrogenase VdGut2 (VD592_6958_Chr4) and non-differentially expressed gene encoding cytosolic glycerol-3-phosphate dehydrogenase VdGpd (VD592_10256_Chr2) were selected for functional analysis based on the transcriptomic analysis induced by cotton extract. The results showed that the conidial production of the two VdGut2 knockout mutant strains decreased by 32% and 41%, respectively, the disease index decreased by 70% and 51%, and the colony growth rate also decreased significantly. On the other hand, the conidial production and disease index of the VdGpd overexpression strains significantly decreased, but the colony growth rate significantly increased on the medium with glycerol as the sole carbon source. Therefore, VdGut2 promotes the formation of V. dahliae conidia, the utilization of carbon source and the pathogenicity to host plant, while VdGpd inhibits the formation of V. dahliae conidia and the pathogenicity to host plant, but promotes the metabolism of glycerol.
Lentinula edodes ranks the second among cultivated edible mushrooms in the world. The formation of brown film (BF) on the mycelial tissue surface is a feature of sawdust cultivation for L. edodes, and this process is critical for ensuring high quantity and quality of fruiting body formation. To understand the molecular mechanisms underlying this process in L. edodes, the high-throughput Illumina was used to analyze the transcriptome data of initial white mycelial sample (LE118), brown mycelial film sample formed under light inducement (LE313C) and white mycelial sample formed in dark (LE313W). The genome of L. edodes W1-26 was used as a reference for transcriptome analysis. In total, 2 215 differentially expressed genes (DEGs) were identified. Of which, 1 216, 1 507 and 1 054 genes were differentially expressed in LE313C/LE118, LE313C/LE313W and LE313W/LE118, respectively. GO enrichment analysis showed that the DEGs were significantly enriched in carbohydrate metabolism process, oxidoreductase activity, hydrolase activity, peroxidase activity, etc. KEGG analysis showed that the degradation of aromatic compounds was significantly enriched in LE313C/LE313W. In the process of BF formation in L. edodes (LE118 to LE313C), the key differentially expressed genes such as glycoside hydrolase, hydrophobins, P450, laccase, glutamate dehydrogenase were screened, suggesting important biological functions of these DEGs. This study provides an important basis for further research on the mechanism of BF brown formation in L. edodes.
The mycelial growth rate, primordial differentiation time, agronomic traits and yield, the content of polysaccharides, total flavonoids, total triterpenes and total phenols of fruiting bodies of five varieties of Sanghuangporus baumii were determined and compared, as well as their scavenging ability on ABTS+ free radicals, DPPH free radicals and hydroxyl free radicals. The results showed that under the same culture condition, there were differences in mycelium growth rate, primordial differentiation time, agronomic characters, yield, active constituents and antioxidant capacity among different S. baumii varieties. S. baumii HN01 has the fastest growth speed, with good growth vigour, rapid differentiation of primordia, good agronomic characters and high yield, and the next best is S. baumii SW. The content of polysaccharides, total flavonoids, total triterpenes and total phenols in S. baumii SW fruiting body is relatively high, and the antioxidant capacity of its active components is the strongest, while the next best is S. baumii HN01. Comprehensive comparison of the total active substances (yield × active ingredient content) among the five cultivated varieties showed that the total crude polysaccharide content of S. baumii HN01 was comparatively high, and the total phenol content of S. baumii SW was comparatively high, while the total flavonoids and total triterpenoids of the varieties were similar. The two varieties, HN01 and SW, could be used as excellent varieties for large scale production.
Cellulase is a group of complex enzymes, which degrades cellulose into glucose and is widely used in biomass degradation, fuel production, and other fields. In this study, using microcrystalline cellulose as the sole carbon source, cellulase production of Trichoderma koningiopsis 8985 and that of T. reesei QM9414 were compared at different time points under liquid state fermentation. The cellulase produced by strain 8985 was detected 12 h after inoculation, and its filter paper cellulase activity reached 50% of the maximum 36 h after inoculation. However, the cellulase activity of QM9414 was not effectively induced at the time. The activities of filter paper cellulase, carboxymethyl cellulase, β-glucosidase and xylanase of the strains at 84 h of fermentation were tested, and those of strain 8985 reached 1.06, 3.62 and 1.80 and 6.67 IU/mL which were 1.72, 1.70, 6.35 and 1.12 times of those of strain QM9414, respectively. The optimal pH and temperature of filter paper cellulase activity of strain 8985 was 4.5 and 50 °C, and the activity was stable in the presence of Fe3+ (≤4 mmol/L) and Cu2+(0-10 mmol/L).
The protective effects of Dictyophora rubrovalvata polysaccharides (DRP) on rats with alcoholic liver injury were investigated. The content of DRP determined by phenol sulfuric acid method was 74.68%±1.32%. The preliminary analysis using Fourier infrared spectroscopy showed that DRP contained α-glycosidic and β-glycosidic linked pyranocyclic polysaccharides. When the concentration of DRP reached 3.0 mg/mL, the scavenging rate of DPPH radical reached 80.12%, the reducing power reached 0.31, and the scavenging rate of hydroxyl radical reached 88.07%. Male SD rats were randomly divided into six groups: normal control (NC), model control (MC), positive control (PC), low-dose (LDRP), middle-dose (MDRP), and high-dose D. rubrovalvata polysaccharides (HDRP) groups. After continuous intragastric administration for 28 d, all rats were euthanized. The serum AST, ALT and TG were examined, and the levels of SOD, GSH, MDA, TNF-α, IL-6 in livers were assayed. The protective effects of D. rubrovalvata polysaccharide (DRP) on alcoholic liver injury in rats was analyzed according to pathological sections. Compared with the MC group, the levels of AST, ALT and TG in the DRP intervention groups were significantly decreased (P<0.05), the levels of SOD and GSH in liver were significantly increased (P<0.05), the contents of MDA, TNF-α and IL-6 in liver were significantly decreased (P<0.05). The pathological phenomena of liver cellular degeneration and necrosis were improved obviously. DRP has a certain antioxidant capacity in vitro, and can alleviate alcohol-induced liver injury in rats, and its alleviating effect is related to the enhancement of antioxidant capacity and the decrease of the expression level of inflammatory factors.
Under the guidance of bioassay, 5ʹ-epi-cryptocin (1) and cryptocin (2) were isolated from the corn culture of an endophytic Pezicula neosporulosa SC1337 derived from Taxodium distichum. Their absolute configurations were determined by comprehensive spectroscopic analysis including NMR and HRESI-MS, as well as X-ray crystallographic data. Both of these two epimers were first simultaneously obtained from metabolite of the same fungus. Crystallography structure of 1 and the NMR data of 2 were reported for the first time. Both of 1 and 2 showed moderate antibacterial acitivities against Staphylococcus aureus, methicillin-resistant S. aureus and Ralstonia solanacearum with MIC of 30 μg/mL. At the dose of 200 μg per paper disk, these two compounds show the same inhibition zone of 7.5, 5.0 and 2.0 mm respectively against Magnaporthe grisea, Ustilaginoidea virens and Curvularia lunata, but inactive on Penicillium italicum and P. digitatum. The data showed that configuration of C-5ʹ had no significant effect on the antimicrobial activities in these two epimers.
Most of the Ganoderma lingzhi medicinal preparations use water extract of fruiting bodies as raw materials. In order to quickly and accurately determine the content of triterpenes in the water extract of G. lingzhi fruiting bodies and related products, a HPLC analysis method with good separation effect is established. Through optimizing the chromatographic column and elution conditions, the Agilent Zorbax SB-Aq C18 chromatographic column (250 mm× 4.6 mm, 5 μm) was selected. Using acetonitrile-glacial acetic acid aqueous solution (0.01%) as mobile phase gradient, under the flow rate of 1.0 mL/min, detection wavelength of 252 nm, and column temperature of 30 °C, 10 ganoderic acids such as ganoderic acid A and ganoderic acid F are well separated. Methodological investigations show that the precision, repeatability, stability, and sample recovery of this analytical method are all less than 5%. This method can be used for quantitative detection of 10 types of ganoderic acids including ganoderic acid C2, ganoderic acid G, ganoderenic acid B, and ganoderic acid B. Comparative analysis of 10 triterpenoids in the raw fruiting bodies, water extracts of fruiting bodies and commercial end products of G. lingzhi indicates that the water extracts of G. lingzhi fruiting bodies contain all of these 10 triterpenes, and the content is 2.52%-6.83% being higher than that in raw fruiting bodies. The triterpene content in the commercial end G. lingzhi products is 0.27%-0.84%. This method advantages the establishment of quality standard of G. lingzhi water extract and its products.
The ‘Gaoyuanyuner 3’ is a new variety domesticated from the wild Auricularia heimuer collected from Baoshan, Southwest China, through selected-breeding and multi-generation screening. The fresh fruiting bodies are moderate in size, with double-layers easily separable and shallow round bowl shape, thick, shiny and soft, unveined. Adopting small rip single bud cultivation method, the fungus begins fruiting at 10-26 °C in 10 days. This new variety is moderately early maturing, tolerant to low temperature, with wide adaptability, high yield, and suitable for cultivation in the low latitude and high altitude area of 1 000-2 000 m.
Hypsizygus marmoreus ‘Minzhen 5’ was bred by protoplast mononuclear hybridization using ‘Minzhen 3’ and ‘Baiyu-01’ strains as parents. The cap is white and hemispherical, with few and small streaks. The protein content of fresh fruit body is 2.1%, and the total amino acid content is 1.43%. The demonstration cultivation shows that the suitable temperature for mycelial growth is 20-27 °C, and the growth temperature of fruiting body is 12-17 °C. The mycelial culture period is 110 d, and fruiting body formation cycle is 28 d. The average yield is 635.17g/bag. The cultivar has the characteristics of short growth cycle, high yield and good marketability, which is suitable for industrial year-round bag cultivation.
