Species of Lactarius subg. Plinthogalus have latex often changing to reddish. Yellowing latex is relatively rare. Lactarius mirus, a species with white latex instantly changing to bright yellow was found from subtropical fagaceous forests in central-southern China. This is the first report of species with yellowing latex in L. subg. Plinthogalus in China. The unique latex, the brown pileus, distant lamellae and big globose spores with high winged ornamentation distinguish it from all other known species, and therefore, it is described as a new species. DNA barcode nrITS-LSU region and morphological description and illustrations are provided. Morphological differences between L. mirus and the other species with yellowing latex, e.g. Malaysian L. flavorosescens and L. pallidior are discussed. The finding of this species adds new evidence showing biogeographically subtropical and tropical affinity of Lactarius in China.
Fungal diversity and community structure in the feces of ruminants (Tibetan antelope) and monogastric herbivores (Tibetan wild ass) in Tibet are investigated by using ITS1 high through-put sequencing method. Five phyla, 15 classes, 32 orders, 45 families and 56 genera were discovered in feces of Tibetan antelopes. Three phyla, 10 classes, 18 orders, 18 families and 28 genera were discovered in feces of Tibetan wild asses. Ascomycota was the dominant phylum, and the relative abundance accounted for 82.70% of the total fungal phyla. Thelebolus, Naganishia and Didymella were the dominant genera, and the relative abundance accounted for 43.91%, 7.38% and 7.03% of the total fungal genera, respectively. The comparison of facal fungal community structure between Tibetan antelope and Tibetan wild ass by using Metastats showed that the fungal community composition in the feces of the two animal species was different, in which the relative abundance of 34 genera showed significant differences.
The roots and rhizosphere soil of 3-year-old Pinus massoniana seedlings (hereinafter abbreviated to ordinary seedlings) breeded by conventional methods and 3-year-old pot culture seedlings breeded by root production method (RPM) (hereinafter abbreviated to RPM seedlings) in Longfu Experimental Base of Hunan Academy of Forestry Sciences were selected as experimental materials, and the ectomycorrhizal fungi (ECMF) of the roots and rhizosphere soil were investigated by Illumina MiSeq sequencing technology for the purposes of finding out the difference community structure of ECMF in different soil microenvironment, providing reference data for artificial inoculation of mycorrhizal fungi and improving the soil microenvironment of ordinary seedlings, and ultimately increasing the survival rate and stress resistance ability of the seedlings. A total of 170 148 ECMF sequences was obtained and they were divided into 20 OTUs (operational taxonomic units, OTUs), belonging to 2 phyla, 3 classes, 7 orders, 8 families and 11 genera. Chao1 richness index, ACE richness index, Simpson diversity index and Shannon Wiener diversity index showed that the OTUs richness of ECMF in ordinary seedling rhizosphere soil was higher than that in RPM seedling rhizosphere soil, and the OTUs richness of ECMF in root sample was lower than that in rhizosphere soil (P<0.05). The dominant genera of ECMF in different samples were different. Amphinema (47.89%) in root samples of RPM seedlings accounted for the largest proportion of ECMF; Tomentella were dominant (70.60%) in ordinary seedlings. Tylospora (62.33%) in RPM seedlings was dominant and Tomentella (55.69%) was dominant in rhizosphere soil samples of ordinary seedlings. Redundancy analysis showed that soil pH had the greatest impact on ECMF, while available phosphorus and organic matters less impacted. Different physical and chemical factors had different effects on community diversity index and dominant genera of ECMF.
In August 2013, purple spots seriously occurred on the leaves and spikelets of oat (Avena sativa) in a field located in Tongwei county, Gansu Province. The disease incidence was 100%. Pathogen isolation was carried out from diseased tissues, and fungal isolates of Pyrenophora (synonym: Drechslera) were obtained. Koch’s procedures were used to verify the pathogenicity of isolate ASA-13. At 8-22°C, isolate ASA-13 produced purple leaf spots on inoculated plants, while yellowish brown to pale yellow leaf spots with black center occurred at 20-25°C, and some leaf spots became striped. Inoculation test at 20°C proved that isolate ASA-13 was able to infect the leaf explants of Avena sativa, A. nuda, Sorghum bicolor, Triticum aestivum, Zea mays and Hordeum vulgare var. nudum. Based on morphological and molecular biological methods the pathogen was identified as Pyrenophora chaetomioides (syn.: Drechslera avenae). BLASTn analysis showed that the rDNA-ITS sequences of isolate ASA-13 (GenBank accession No. MN560117) had a 99.36% similarity with those of D. avenae isolate DA16 (GenBank accession No. AF260328.1). Temperature gradient analysis showed that 25-30°C was optimal for mycelial growth of the pathogen on PDA.
Lilium brownii var. viridulum is medicinal and edible lily mainly cultivated in Jiangxi Province. The tissue culture seedlings in some production regions were found to be attacked with a disease named as “soft rot”. The leaves and stems or even the whole plants were rotten gradually. The pathogen was isolated and identified base on morphological characteristics, pathogenicity test, multilocus sequence alignment and phylogenic analysis. Morphological identification tentatively recognized the pathogen as Acremonium sclerotigenum. Further analysis of nucleotide sequences of rDNA internal transcribed spacer (ITS), large ribosomal subunits (LSU), small ribosomal subunits (SSU) and beta-tubulin (Tub2) of the fungal isolate indicated that it was highly clustered to A. sclerotignum clade in the phylogenetic tree. The pathogenic fungi was confirmed as A. sclerotignum.
In order to explore whether the temperature-regulated aflatoxin biosynthesis affects the morphology of Aspergillus flavus mycelia, comparative observation on the ultrastructure of mycelia in different developmental stages grown in various temperatures was carried out based on scanning and transmission electron microscopy. Scanning electron microscope observation showed that filamentous viscous particles appeared on the mycelium surface in 24 hour (h) and 44h after inoculation at 28°C, and the mycelium gradually appeared to be shrinked, and then collapsed and distorted in 48h and 72h, while the mycelia grown at 37°C remained thick and robust in 24-72h. Transmission electron microscope observation displayed that large vesicles appeared in hyphal cells cultured at 28°C in 24h after incubation, and the internal organelles were indistinct in 44-72h. The organelles at 37°C were clear, and the number of mitochondria and liposome increased obviously in 44-48h, and the septal structure was observed at 72h. The ultrastructure of Aspergillus flavus mycelia cultured at 30°C and 40°C also verified the above findings. Taken together, 28°C and 30°C promoted the aflatoxin biosynthesis, but accelerated senescence of mycelia. On the contrary, 37°C and 40°C were unfavorable to the biosynthesis of aflatoxin, but beneficial to the growth of mycelia, and the senescence process of mycelia was relatively slow. This study showed that the aflatoxin biosynthesis was closely related to the internal morphological changes of Aspergillus flavus mycelia.
Shiraia bambusicola is an important medicinal species of ascomycetes, and there have been disputed on its classification and affiliation mainly due to difficulty in morphological characterization of species. In this study, based on self-testing genome of S. bambusicola S4201, combined with the genomic data of S. bambusicola GZAAS2.1243 and Shiraia sp. slf14 catalogued in the database of Genome Warehouse (GWH) and GenBank respectively, the classification status of S. bambusicola was reexplained more closely to the nature affinity. Four gene sequences, nrSSU, nrLSU, tef-1α and rbp2, were selected for the phylogenetic analysis at order level, in comparison with 74 species of ascomycetes catalogued in the Assembling The Fungal Tree of Life (AFTOL); three gene sequences, ITS, nrLSU and tub2, were selected for the phylogenetic analysis at family level, in comparison with 30 species of Pleosporales accessioned in GenBank database. Maximum likelihood (ML) and Bayesian inference (BI) analyses were used to construct phylogenetic trees, respectively. The results support the establishment of independent Shiraiaceae, and Shiraiaceae should be included in the order Pleosporales. There may exist hidden species in the genus Shiraia.
Zn(II)2Cys6 transcription factor (C6 zinc) plays a significant role in the synthesis of secondary metabolites in fungi. In this study eleven genes that encode C6 zinc from the whole Sanghuangporus sanghuang genome were identified by using local BLAST. Bioinformatics analysis method were utilized to analyse the conserved domains as well as the primary and secondary structures of protein products. Protein phylogenetic tree was constructed to classify the C6 zinc in S. sanghuang. Besides, their gene expressions under different carbon source and nitrogen source culture conditions were analyzed by semi-quantitative PCR. The result shows that the eleven S. sanghuang C6 zinc proteins are unstable and hydrophilic, with phosphorylated modification sites, but without glycosylation modification sites or signal peptides, and all of them locate in the nucleus. The secondary structure is mainly composed of random coil and alpha helix. These S. sanghuang C6 zinc proteins were classified into two main branches in phylogenetic trees. Among them, the conserved domains of the groupⅠproteins are distributed at the N-terminal, and the others in branchⅡare distributed at the C-terminal. Eleven S. sanghuang C6 zinc transcription factors were differentially expressed in mycelia cultured on different media, and inositol medium as well as lactose medium could effectively promote the expression of most of them. The preliminary analysis of the gene cluster suggests that SHCZ4 might be a pathway-specific transcription factor of NRPS-PKS hybrid metabolites. These results will provide a reference for the study of transcription factors related to the synthesis of secondary metabolites and for the mining of potential secondary metabolic-related gene clusters in S. sanghuang.
Secreted proteins of filamentous fungi are closely related to fungal pathogenicity. At present, there are few reports on the protein secretion pathway and the regulatory mechanism(s) in pathogenic fungi. For establishing a convenient and efficient genetic research system for investigating the regulation of fungal secretory proteins in Cryphonectria parasitica that causes chestnut blight, the reporter vectors for secretory expression were constructed based on our previous secretory proteomics analysis by using two signal peptides SP1 and SP2 with the highest expression level, to fuse with the GUS gene. The resulting constructs, namely pCPXBle-SP1-GUS and pCPXBle-SP2-GUS, were then transformed into the wild-type C. parasitica strain EP155. The transformant strain SP1-9 showing the highest secreted GUS efficiency was used to generate the T-DNA insertion mutants by Agrobacterium tumefaciens-mediated transformation (ATMT) method. Out of the 576 such T-DNA insertion mutants, two mutants significantly decreased GUS secretion. This study successfully established a high-throughput transformation system for investigating the secretory pathway in filamentous fungi, and obtained mutants having defect of protein secretion, being beneficial to future studies on molecular mechanism of fungal secretory pathway.
Flammulina filiformis is one of the most popular edible mushrooms in China and Japan, ranking fourth among the most important cultivated mushrooms according to its production and consumption. Its active constituents, molecular markers, gene identification, etc. have been extensively studied, however, nothing has been reported about its reference-gene stabilities, resulting that there is no available data concerned in the study of gene expression. In this study, 18S ribosomal RNA (18S), 28S ribosomal RNA (28S), 60S ribosomal protein L18 (Rpl18), actin 1 (Act1), glyceraldehyde-3-phosphate dehydrogenase (Gapdh), translation elongation factor EF1-alpha (Ef1A), DNA-direct RNA polymerase subunit 2 (Rpb2), cytochrome c oxidase subunit 1 (Cox1) and cytochrome b (CytB) were employed as reference-gene candidates to evaluate their stabilities using algorithms of geNorm, NormFinder, BestKeeper and RefFinder. Comparative results showed that, as a single gene, Act1 was the most stable reference gene, and CytB was the least stable, but a single reference gene was inadequate for normalization in RT-qPCR. Average expression stability values M generated by geNorm indicated that CytB and Rpb2 were the most stable genes and could be taken as suitable reference gene set. This study first evaluated reference-gene stabilities in F. filiformis, and might provide reference for gene expression analysis of this species.
Mycelia with three different morphology of Ophiocordyceps sinensis TZ8-1 isolated from monoascospores were used as experimental materials. RNA of mycelium was extracted, and cDNA was obtained by reverse transcription. Eleven housekeeping genes were selected as candidate reference genes (18S rRNA, APRTase, β-TUB, RPL2, EF1-α, PGI, PGM, H+-ATPase, ACT1, UBQ and GAPDH). Primers were designed based on the genome annotation results of Ophiocordyceps sinensis and quantitative amplification was conducted by real-time fluorescence quantitative PCR (qRT-PCR). The expression of stability was evaluated by geNorm, NormFinder and BestKeeper algorithms, and the evaluation of results were combined by RefFinder to screen the optimal internal reference genes. The results showed that all the 11 candidate reference genes could be used as reference genes in the mycelium stage of Ophiocordyceps sinensis. The three most stable ones were UBQ, PGE and ACT1, and the three less stable ones were GAPDH, RPL2 and β-TUB.
Ku70 and Ku80 are key components of the nonhomologous end joining (NHEJ) pathway. The strains of Δku70 and Δku80 in some filamentous fungi are usually used as chassis strains because deletion of ku70 and ku80 can increase the homology-directed repair (HDR) frequency and improve the efficiency of target gene knock-out. In this study, homologues of ku70 and ku80, Cmku70 and Cmku80, were identified from the genome of Cordyceps militaris, which encoded two proteins with relative molecular weight of 71.50kDa and 80.96kDa, respectively. There are Ku core domains in both proteins. Subcellular localization analysis indicated that both proteins were targeted to cell nucleus. Phylogenetic analysis revealed that Ku70 and Ku80 proteins were widely found in fungi and relatively conserved. Cmku70 was knocked out using Agrobacterium tumefaciens-mediated homologous recombination in C. militaris. It was found that knocking out of Cmku70 did not affect C. militaris asexual development including mycelial growth, color transformation under light exposure, conidiation and conidial morphology, but entirely inhibited the fruiting body formation. Consequently, the Cmku70 deletion strain is not suitable to be used as chassis strain for characterization of genes responding for fruiting body development.
Aspergillus niger 3.316 is a heat-resistant filamentous fungus strain with a maximum growth temperature of 47°C, having an application potential for fermentation industry. In order to make full use of its functionality in industrial fermentation, a comprehensive understanding of the strain information is required. The whole genome of Aspergillus niger 3.316 strain was sequenced through CLR sequencing method of the PacBio Sequel sequencing platform. The results showed that the genome finally obtained 15 contigs with a total length of 34 956 132bp and GC content of 49.21%, and 10 032 coding genes were predicted. There are 6 901, 2 118 and 9 494 genes annotated in the GO, KOG, and KEGG databases, respectively. Through analysis and comparison, it is found that the heat tolerance of Aspergillus niger is closely related to the antioxidant-related genes superoxide dismutase (SOD) and catalase (CAT). This finding provides reliable information for the follow-up study on the heat resistance characteristics of Aspergillus niger 3.316, and solving the high energy consumption, high production costs and high temperature environment affecting industrial fermentation.
Neurospora crassa is a highly efficient cellulose-degrading fungus in ascomycetes, which can directly use cellulose as a nutrient source for growth. In this study, the overexpression strain of sterol reductase gene erg24 was constructed by genetic engineering technology. Saccharose, wheat bran, corn straw, wheat straw, poplar sawdust, and rice straw powder were respectively used as carbon source to culture wild-type and erg24 overexpression strain. The expression levels of erg2, erg24, and erg6 related to ergosterol synthesis were determined by semi-quantitative RT-PCR. Ergosterol accumulation was tested by HPLC method. The results showed that the high expressions of erg2, erg24, and erg6 occurred in the culture media using corn straw, poplar sawdust or rice straw power as carbon source. Under different culture conditions, the ergosterol yield of erg24 overexpression strain was significantly higher than that of the wild-type strain of N. crassa. The accumulation of ergosterol reached the highest level (30.53μg/mg) in the substrate with poplar sawdust. These results proved that erg24 is one of the key genes during the biosynthesis of ergosterol in N. crassa. Higher ergosterol yield can be obtained by using corn straw, wheat straw, poplar sawdust, and rice straw powder as carbon source, and these results provide a valuable reference to produce ergosterol by fungi using agricultural wastes.
Lentinula edodes ranks second in production of edible mushroom in the world and has a long cultivation history. The development of L. edodes can be divided into four stages, growth stage (G), light-induced browning (B), primordial formation (P) and fruiting body development (FB). Mycelial browning and primordial formation are very important stage for transformation of L. edodes from vegetative stage to reproductive stage, which are crucial to the yield and quality. Transcription of L. edodes in the preceding three development stages was analyzed by using three different culture materials as replicates. Principal component and correlation analysis showed that the expression characteristics of the genes were similar within the same stage. Using transcriptome of growth stage as control, the genes related to mycelial browning maturation and primordial stage were obtained, and these genes were analyzed by GO and KEGG. WGCNA was used to analyze the differentially expressed genes, hub gene and the gene modules related to mycelial browning transformation and primordial formation. As a result, 17 important genes in mycelial growth stage, 167 in browning stage and 67 in primordium formation stage were obtained by combining differential gene and gene module analysis. The combination of multiple analysis provides us with a more efficient method for screening candidate genes.
Pleurotus eryngii protein (PEP) was heated at 50°C, 60°C and 70°C for 0 to 30min to investigate the effect of heat-moisture pretreatment on its physicochemical properties, structure and functional characteristics in this research. The results showed that the hydrophobicity of PEP increased first and then decreased (P<0.05) and its total sulfhydryl content decreased first and then increased (P<0.05) after the moist-heat treatment. Furthermore, the secondary structure of PEP was affected. For example, the α-helices content of PEP decreased after moist-heat treatment at 50°C and 60°C, whereas, it increased at 70°C. The content of β-sheet of PEP decreased, while its β-turn and irregular curl increased. In terms of functional properties, after moist-heat treatment at 50°C, 60°C and 70°C within 20min, the emulsifying and foaming properties of PEP were increased, respectively (P<0.05). Therefore, the wet-heat treatment could enhance the functional properties of PEP and improve its application in food processing.
The aged contaminated soil in typical coal areas was taken as the remediation object to study the degradation effect of different dosages of humic acid on the total quantity of 4-ring polycyclic aromatic hydrocarbons (PAHs) in soil degraded by Fusarium sp. ZH-H2 and the degradation effect of each monomer, and to analyze the dynamic characteristics of degradation of 4-ring PAHs enhanced by humic acid. As a result, the removal rates of the total quantity of 4-ring PAHs and each monomer were significantly increased under ZH-H2 treatment after adding different dosages of humic acid, and increased efficiency ranged in order of HF3 (2.5g/kg)>HF1 (0.5g/kg)≈HF2 (0.1g/kg)>H. When added content of humic acid was 2.5g/kg, the removal rates of the total PAHs and each monomer were as high as 32.44% and 35.06% respectively, and monomer Pyr was prominently degraded. Under the treatment with and without humic acid, the PAH degradation rate of ZH-H2 was the fastest in 0-4d, with total degradation rate of 43.70μg/(kg·d), and then the degradation rate showed a weakening trend. Compared with the treatment without humic acid, the Pyr degradation rate of humic acid-enhanced ZH-H2 was up to 57.05%. The total quantity tidy of PAHs and the degradation rate of each monomer were in line with the first-order dynamic equation. The coefficient of correlation and absolute value of the reaction rate constant under the treatment with humic acid were significantly higher than those under the treatment without humic acid. Compared with the treatment without humic acid, the half-life (55-69.3d) of 4-ring PAHs after humic acid enhancement was 0.76-1.77 times shorter than the natural attenuation (96.3-177.7d), indicating that humic acid greatly promoted the degradation rate and shortened the degradation time. To sum up, adding 2.5g/kg humic acid to Fusarium sp. ZH-H2 was effective on degradation of PAHs, and the degradation period was shortened. Our results provide technical improvement for in-situ remediation of contaminated aged soil.
The fermented products of Ganoderma lingzhi were obtained by large-scale submerged fermentation, and ten compounds were isolated by silica gel column chromatography, reversed-phase silica gel column chromatography and recrystallization. Through NMR and MS spectrum, they were identified as the mixture of (9S,10R,11E,13R)-9,10,13-trihydroxyoctadec- 11-enoic acid (1) and (9S,10R,11E,13S)-9,10,13-trihydroxyoctadec-11-enoic acid (2), 12S*,13S*- dihydroxy-9-oxo-10(E)-octadecenoic acid (3), 9R*,10R*-dihydroxy-13-oxo-11(E)-octadecenoic acid (4), 12S*,13R*-dihydroxy-9-oxo-10(E)-octadecenoic acid (5), 9S*,10R*-dihydroxy-13-oxo- 11(E)-octadecenoic acid (6), 10(S)-hydroxy-8(Z)-octadecenoic acid (7), 12-oxooctadeca-8,10- dienoic acid (8), 9,12-dihydroxy-10-eicosenoic acid (9) and 9-oxooctadeca-10,12-dienoic acid (10). They were all unsaturated fatty acid compounds containing hydroxyl or ketone groups. These compounds were obtained for the first time from fermentation products of Ganoderma lingzhi, with antitumor activity in vitro to some extent. The IC50 values of compound 8 and compound 10 against tumor cells L1210 were 13.00μmol/L and 16.88μmol/L, respectively, and the effectiveness of them inhibiting the proliferation of K562 cells was also excellent. This result proved compound 8 and compound 10 were natural products with antitumor potential.
Thirteen species of wild Ganoderma were isolated, and liquid fermentation was conducted under the same conditions to compare their content of intracellular triterpenoids and polysaccharides. The results showed that the content of triterpenoids and polysaccharides was significantly different among 13 Ganoderma species. The content of triterpenoids was higher in Ganoderma mastoptorum, G. lucidum and G. applanatum than that in other tested species, and the content of polysaccharides was higher in G. applanatum, G. sinense and G. brownii than that in other tested species. The wild strain of nowaday widely cultivated G. lingzhi produced less triterpenoids and polysaccharides as compared with other wild Ganoderma species tested. Our results show that there are still more Ganoderma species having potential value for further exploration.
Traditional Chinese medicine is widely used for pulmonary inflammation treatment. The S protein on the outer envelope of the new acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is the key factor that determines the virulence of the virus and the main antigen. In this study, SARS-CoV-2 virus S protein and bacterial lipopolysaccharide (LPS) were used to induce a pulmonary inflammation model and the effect of Cordyceps militaris powder on the pro-inflammatory factors, monocyte/macrophages and myeloid-derived suppressor cells (MDSCs) in mouse model was initially explored. It was found that C. militaris powder could reduce the expressions of TNF-α, IL-6 and IL-10 in the blood serum, the numbers of macrophages in the lung tissues, alveolar lavage fluid and periphery blood, and the distribution of MDSCs in the periphery blood and spleen of SARS-CoV-2- and LPS-injured mice. Further studies proved that C. militaris powder could also decrease the expression of hydroxyproline and the distribution of fibroblasts in the lung tissues of the SARS-CoV-2- and LPS-injured mice, thereby alleviating the level of lung fibrosis. Results of qRT-PCR experiments showed that treatment of C. militaris not only reduced the levels of TGF-β R1 in the lung tissues of SARS-CoV-2-injured mice, but also reduced the expression of smad2 in the lung tissues of SARS-CoV-2-injured and LPS-injured mice. Thus we believed that C. militaris powder might alleviate the lung inflammation and fibrosis induced by S protein of SARS-CoV-2 virus and LPS via TGF-β R1/smad2 pathway.
Antioxidant activities and chemical components of ethanol extracts of fruit bodies of wild Sanghuangporus sanghuang and S. vaninii were compared. DPPH scavenging activity, superoxide anion scavenging activity and β-carotene bleaching assay were used to compare the antioxidant activity. The results showed that both S. sanghuang and S. vaninii had strong antioxidant activity, and the antioxidant activity of S. vaninii was significantly stronger than that of S. sanghuang. The content of total flavonoid and total polyphenol in the ethanol extract of S. vaninii were higher than that of S. sanghuang. Ultra performance liquid chromatography tandem triple quadrupole time-of-flight mass spectrometry (UPLC-Triple-TOF-MS) was used to compare the differences of chemical components in the ethanol extracts. Nineteen phenolic compounds were common to S. sanghuang and S. vaninii, and additional three phenolic compounds were identified from S. vaninii.
The protective effect of fermentative filtrate dried powder of Taiwanofungus camphoratus (AC) on mice suffered from alcoholic liver disease (ALD) was investigated. Mice were randomly divided equally into five experimental groups: normal control group, model group, low dose AC group (350mg/kg), medium dose AC group (700mg/kg), and high dose AC group (1 050mg/kg). It was found that AC could reduce serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in mice. AC also significantly decreased the levels of non-esterified fatty acid (NEFA) content, total cholesterol (TC), and triacylglycerol (TG). H&E and Oil-Red-O staining treatment indicated that AC improved cell damage and reduced lipid accumulation in mouse liver. In summary, AC has an ameliorative effect on ALD probably through ameliorating ethanol-induced hepatic steatosis and injury through reducing lipid accumulation during the development of fatty liver. Our findings suggest that AC has potential for developing a health dietary supplement or prescription for ALD.
Lignin is a non-crystalline complex phenolic polymer with three-dimensional network, which is regarded as a natural barrier of lignocellulosic biomass against degradation. In recent years, exploring and developing of microbial resources for efficient lignin degradation has attracted much attention. In this study, a newly isolated strain Z-1 with potential lignin degradation ability was identified as Trametes versicolor. The qualitative plate experiment analysis suggested that T. versicolor Z-1 might possess strong ability to produce peroxidase and laccase. Using lignin as the sole carbon source, the rates of lignin degradation and decolorization by T. versicolor Z-1 reached 13.38% and 26.43%, respectively. Detection of enzymatic activities showed that laccase and MnP was mainly responsible for lignin degradation. FT-IR, SEM and GC-MS analyses confirmed the impressive capacity of lignin degradation by T. versicolor Z-1, and the degradation pathway consists of cleavage of phenol ether bond, oxidative breakage of aromatic side chain and aromatic ring opening reaction. Furthermore, T. versicolor Z-1 showed great capacity to aromatic dye decolorization, and the decolorization rate of Congo red, Malachite green and Coomassie brilliant blue R-250 reached 100%. This study suggested that T. versicolor Z-1 might be a promising candidate for industrial lignin degradation and aromatic dye decolorization.
Efficient lignin-degrading fungal strains were screened by using guaiacol- and aniline blue-containing solid media. Using Phanerochaete chrysosporium CGMCC 5.0776 as a control, cornstalk was pretreated with the selected strains. The degradation rates of lignin and cellulose, and the activities of laccase, manganese peroxidase (MnP) and lignin peroxidase (LiP) were determined. Two strains with higher activities of laccase or MnP were screened from 16 white-rot fungal strains. Based on morphology and molecular biology, they were identified as Trametes betulina (ZT-153) and B. fumosa (ZT-307). The lignin degradation efficiency on cornstalk was 13.60% by T. betulina ZT-153 and 21.87% by B. fumosa ZT-307, or respectively 1.58% and 9.85% as against P. chrysosporium CGMCC 5.0776, and the degradation rate of cellulose was 4.10% and 4.50% respectively. During the pretreatment of cornstalk, T. betulina ZT-153 showed active in degrading laccase and MnP, while B. fumosa ZT-307 only showed active in degrading LiP. Bjerkandera fumosa ZT-307 showed the highest lignin degradation ability, and it has potential and application prospects in comprehensive utilization of cornstalk resources.
Talaromyces marneffei is the causal agent of talaromycosis. It has been proved that T. marneffei has opposite mating types which showed geographical differences. Mating type plays a role in antifungal susceptibilities of fungi like Aspergillus fumigatus and Candida albicans, but whether it works in drug sensitivity of T. marneffei is still unknown. In this study, the susceptibilities of T. marneffei with different mating types (MAT-1 and MAT-2) against seven antifungals were tested. The data showed that T. marneffei strains with MAT-2 were less sensitive to itraconazole than those with MAT-1. The result suggests that mating type may play a role in antifungal susceptibility of T. marneffei.
