Metarhizium robertsii is an important entomopathogenic fungus, widely used for control of agricultural pest insects and vectors of human diseases. Recent studies showed that microRNAs might play important roles in fungal growth and development. However, the function of miRNAs in regulating sporulation in M. robertsii has not been reported. In this study, a novel miRNA, mro-miR-33, previously identified from our small RNA deep-sequencing libraries was down regulated during fungal sporulation. Over-expression of mro-miR-33 in wild type M. robertsii significantly reduced conidial production. The brlA gene regulating conidiophore development was significantly down-regulated in mro-miR-33 over-expressing strain. However, disruption of mro-miR-33 significantly increased conidial production compared to wild type. These results suggest that mro-miR-33 negatively regulates conidiation in Metarhizium robertsii.
Pythium oligandrum is a mycoparasitic biocontrol agent that is able to antagonize several plant pathogens and promote plant growth, without harm to any animal, plant or the environment. In this study, 0.8mol/L D-mannitol, 25mmol/L CaCl2 and 10mmol/L Tris-HCl were used as osmoticum, and the mycelium of Pythium oligandrum was enzymolyzed for obtaining protoplasts in mixture of lysing enzyme, cellulose and lyticase. The regeneration ability was recovered by liquid suspension culture of the obtained protoplasts for one day and the protoplasts were then coated onto a culture plate for growth of thallus. By using this method, the number of the protoplasts could reach 1×109CFU/mL, with activity of more than 80% and the regeneration rate of 32.9%. The method was convenient to carry out and stable. The protoplasts obtained were high in the quality and plentiful, which could meet the demands for application of genetic transformation, cell fusion and culture, and other purposes.
Eurotium spp. are the dominant microbes during the processing of brick tea and play a key role in the formation of quality, flavor and physiological functions of Fuzhuan Tea. By agar plate tests, eighteen Eurotium strains were examined for their ability to produce extracellular macromolecular hydrolases. The results demonstrated that there were eight strains showing positive activity of tannase, ten strains showing amylase activity, six strains lipase activity, ten strains cellulase activity and nine strains protease activity. The enzyme tests indicated that strain LP-7 produced all five kinds of the hydrolases, strains LP-8, FZ-3 and QL-2 produced four kinds of the enzymes, while strains LP-5, LP-6, FZ-1, FZ-2, FZ-4 and QL-1 produced three kinds of the enzymes. The effects of different solid-state fermentation conditions on secreted protein production of strain LP-7 were studied. Green tea 10g with moisture content of 80%, inoculated with 1mL of conidial suspension (5.0-6.0×107spores/mL) of Eurotium sp. strain LP-7 and incubated at 28°C for 21 days showed obvious effects of promoting the protein production of fermented tea. The extracellular proteins of fermented tea using strain LP-7 as inoculum were separated by two-dimensional gel electrophoresis and identified by MOLDI-TOF-TOF. A total of ten extracellular proteins were identified, including seven enzyme proteins, such as arabinoxylan, superoxide dismutase [Cu-Zn], tannase, cellulose-binding GDSL lipase, feruloyl esterase, aromatic compound dioxygenase, and glycoside hydrolase enzyme. Under dry condition, Eurotium spp. can produce abundant extracellular proteins, which provides a theoretical basis for the explanation of the mechanism and function of Eurotium enzymes in fermentation of tea.
Order Agaricales belonging to Basidiomycota, Agaricomycotina is the most abundant group in fungal kingdom. Fungi belonging to Agaricales could be highly effective saprophytes and parasites or symbionts of other plants or animals, which play important roles in maintaining environmental balance. The compositions of carbohydrate-active enzymes (CAZymes) and oxidoreductases in 51 fungal strains were revealed based on 51 fungal genomes and the differences of degradation mechanism of white-rot (WR), brown-rot (BR), saprobic (S), mycorrihizal (M), plant-pathogenic (PP), facultatively parasitic (FP), and animal-symbiotic (AS) fungi and other fungi of unknown ecological (N) and nutritive types were compared. The results revealed the average numbers of CAZymes families detected were 134, 93, 101, 127, 93, 61 and 32, and the numbers of the genes belonging to different CAZymes families was 398, 240, 463, 407, 418, 131 and 38 in wood-decaying (white-rot and brown-rot), saprobic, mycorrihizal, facultatively parasitic, other unknown ecological type, plant-pathogenic and animal-symbiotic fungi, respectively. Wood-decaying fungi covered the most abundant CAZymes families and parasitic and saprobic fungi had the highest number of genes homologous to CAZymes. The average number of genes related to lignocellulose degradation was 86, 32, 101, 86, 104, 36 and 10 in WD (wood decaying), M, FP, S, N, PP and AS respectively. The average number of oxidoreductases in the fungi above-mentioned was 44, 35, 48, 53, 59, 6 and 29. CAZymes and oxidoreductases in Agaricales varied significantly and the diversity of them was very high. There was no obvious relationship between enzymes related CAZymes and oxidoreductases and ecological types. This research enriched the diversity of mechanisms of degradation of lignocellulose, however, the activities of enzymes need experimental designs for verification and further evolution analyses of protein family.
Trametes hirsuta XYG422 with high laccase activity was selected by liquid fermentation from nine white-rot fungal stocks. Single-factor experiment was designed to optimize the laccase producing ability according to different cultural media and conditions. Then, corn straws were used to assess the degradation by this strain. The optimized nitrogen sources for XYG422 laccase production were corn flour and tartaric acid ammonium. The optimized nutritional ingredients and fermentation conditions were corn flour 40g/L, tartaric acid ammonium 2g/L, incubation temperature of 30°C, culture medium pH value of 8.0, inoculum quantity of five fungal agar plugs (diameter 1cm) and rotary rate of 180r/min. Tween-80 and 2,5-dimethyl aniline at low concentration promoted laccase production. Under the optimized conditions, the laccase activity produced in XYG422 was significantly increased up to 41.6U/mL. Trametes hirsuta XYG422 exhibited the best corn straw biodegradation effect. After 60d inoculation, the lignin degradation rate reached 83.54%, and the cellulose and hemi-cellulose degradation rate was 50.65% and 19.53% respectively.
The mycelium of a Xylaria sp. strain isolated from Boletus sp. was obtained through liquid submerged fermentation method. The immunomodulatory, antitumor, and antioxidant activities of the crude polysaccharide, the petroleum ether and chloroform extracts from the mycelium were evaluated. The result showed that the petroleum ether and chloroform extracts had good antitumor activity against SPCA-1 lung cells, and the antioxidant activity of the two extracts and the stimulation effect of crude polysaccharide on macrophages to release NO were not significant. Inhibitory rates of SPCA-1 were significantly increased by 60.0% and 68.41% respectively after the treatment by 100μg/mL petroleum ether extract and 100μg/mL chloroform extract of the Xylaria sp. strain. Flow cytometry result revealed that 50μg/mL petroleum ether extract and 50μg/mL chloroform extract of the Xylaria sp. strain brought about apoptosis of SPCA-1 cells and the apoptosis rates reached 25.4% and 26.3% respectively. Further investigation showed these extracts could increase expression of P53, caspase-3 and Bax, and decrease expression of anti- apoptotic protein Bcl-2. The anti-tumor activity of the petroleum ether and chloroform extracts had relation with ROS-triggered apoptosis. The protective autophagy of SPCA-1 was also activated by these extracts, and the inhibition of autophagy could stimulate inhibition effect of Xylaria sp. on SPCA-1 proliferation.
A white rot fungus strain CB1 was isolated and purified. The strain shares highest similarity with Cerrena unicolor in morphology and culture characteristics as well as the ITS sequence. It shows remarkable capability of decolorizing reactive black and reactive red dye. The decolorization rate for reactive black dye was 96%, 93%, 65%, 55%, and 40% and for reactive red dye 98%, 95%, 91%, 87%, and 83% at the dye’s concentration of 10, 50, 100, 250, and 500mg/L, respectively.
An endophytic fungus isolated from Fritillaria cirrhosa was identified as Fusarium tricinctum by combining molecular biological methods and morphological characteristics. The DPPH radical scavenging activities, total antioxidant capacities (ABTS assay), the reduction power (FRAP assay), total phenolic content (TPC), total flavonoid content (TFC) and total saponin content (TSC) of the petroleum ether extract (PEE), ethyl acetate extract (EAE), n-butyl alcohol extract (BAE) and ethanol extract (ETE) of the strain CBY11 of the fungus were determined. The results indicated that EAE, BAE and ETE exhibited higher DPPH radical scavenging activities (IC50 values 1.95mg/mL, 1.19mg/mL and 1.64mg/mL, respectively), higher total antioxidant capacities (IC50 values 0.43mg/mL, 0.58mg/mL and 0.43mg/mL, respectively) and relatively lower reduction power. The antioxidant activities of PEE were totally lower. TFC, TPC and TSC of EAE, BAE and ETE were significantly higher than those of PEE (P<0.05). There were positive correlations between TFC, TPC and TSC and the antioxidant activities to a certain degree. HPLC analysis indicated that EAE possessed multiple phenol acid compounds with higher antioxidant activities, such as apigenin. GC/MS analysis revealed that PEE had a few phenol acid compounds with antioxidant activities, mainly hydrocarbon compounds. The present study reveals that endophytic fungus Fusarium tricinctum CBY11 has ability producing plentiful bioactive compounds with antioxidant properties, being possessed of multiple utilization values.
Suspension quantitative germicidal test, field test, stability test and toxicity evaluation were carried out to observe the germicidal efficacy of a new disinfectant, polyhexamethylene biguandine, against Hepialus larva pathogen Isaria farinosa. The results showed that disinfection rate against Isaria farinosa spores by using 2g/L polyhexamethylene biguandine solution reached more than 99.00% and field test also obtained the same result. Polyhexamethylene biguandine concentration the solution decreased only 2.10% and 3.20% respectively when neat solution and diluted solution stored in three months and one month respectively at 37°C. The disinfection solution of 10g/L did not cause significant mortality of Hepialus larvas. In conclusion, polyhexamethylene biguandine solution was qualitatively stable with good sterilizing effect and safety and could be used as disinfectant for sterilizing fodder and feeding box of Hepialus larvas.
Three new records of cercosporoid fungi from China, Pseudocercospora calopogonii on Calopogonium mucunoides, Pseudocercospora macarangicola on Macaranga denticulata, and Pseudocercosporella dioscoreae on Dioscorea subcalva are reported. Descriptions, illustrations, and discussions are provided. Examined specimens are deposited in Herbarium Mycologicum Academiae Sinicae (HMAS) and Herbarium of Mycology of Jilin Agricultural University (HMJAU).
This study obtained 67 regenerative strains of Agrocybe cylindracea mutated by atmospheric and room temperature plasma (ARTP) mutagenesis, growing in screening mediums containing litchi sawdust. The preliminary 12 regenerative strains had obvious antagonism against the original ones. After rescreening seven regenerative strains with faster growth and better vitality were obtained, and they were detected by using electrophoresis method to confirm superiority of the regenerative strains. A regenerative strain named AL20 was found to be excellent for decomposition of litchi sawdust, and the association coefficient between strain AL20 and the original strain was 0.6, indicating that strain AL20 was genetically different from the original one; besides, the mycelial growth rate of strain AL20 was 3.13mm/d, and biological efficiency up to 73.15%, respectively 0.21mm/d and 9.03% higher than the original strain, It can be preliminarily confirmed that strain AL20 was a mutant with high-efficient utilization of litchi sawdust.
