Jiejin Mountain National Forest Park located in northeastern Heilongjiang Province is abundant in biological resources. Up to the present the macrofungal resources in the area is still uncertain. In this work, random inspection method was used to explore the macrofungal resources of the area. Identification of the specimens was carried out on the basis of morphology combined with molecular biology methods. Relevant literature was consulted to evaluate the economic value of the fungi. The results indicate that there are 209 species of macrofungi in this forest park, belonging to 2 phyla, 5 classes, 19 orders, 63 families, and 111 genera. Of these 72, 52, 32 and 30 are respectively edible, medicinal, ectomycorrhizal and poisonousing, accounting for 34.45%, 24.88%, 15.31%, 14.35% of the total respectively. Seventy-two species cause rot decay and 78 species have other values, accounting for 34.45% and 37.32% of the total respectively. The dominant families having more than 10 species each were Amanitaceae, Mycenaceae, Polyporaceae, and Russulaceae. The dominant genera each containing more than 5 species were Amanita, Inocybe, Laccaria, Marasmius, Mycena, Pluteus, Russula and Trametes. Most of these fungi are cosmopolitan and boreal-temperate. One species is found to be endangered, one vulnerable and two nearly threatened. There are two Chinese endemic species.
A survey and evaluation of macrofungi in the Fuyan Nature Reserve in Zheng’an County, Guizhou Province was conducted. The species composition, number of dominant families and genera, geographical distribution patterns of species, resource evaluation, and endangered level of species in the area were analyzed. In total, 392 species of macrofungi were found in the area, belonging to 152 genera in 70 families of 26 orders in 5 classes. Among them, 212 species were newly recorded in the area. The dominant families were Russulaceae, Polyporaceae, Omphalotaceae, and Mycenaceae etc., with species accounting for 51.78% of the total. The dominant genera were Russula, Gymnopus, Marasmius, Mycena, and Amanita etc., with species accounting for 31.38% of the total. The macrofungi in the Fuyan Nature Reserve was mainly composed of cosmopolitan families and cosmopolitan genera with northern temperate characteristics in some degree. Cosmopolitan species and northern temperate species were dominate. There were 74 edible fungi in the area; medicinal and edible-medicinal species totaled 62 and 54, respectively. There were 34 toxic species. The endangered level evaluation showed that the ecological environment in the surveyed area was adaptive for maintaining diversity of macrofungi and the significantly threatened species had not been found, however, there were four nearly threatened species (NT). Seventeen endemic Chinese species were found. This study provided a reference for conservation and sustainable development of macrofungi species in this area.
With the rapid development of urbanization, human activities exert significant impacts on soil microorganisms in various urban habitats. However, the composition and diversity of fungi in different urban habitats remain poorly understood. In this study, 240 soil samples were collected from suburban agricultural land, hospital green spaces, sewage treatment plant green spaces, and zoo green spaces across 20 highly urbanized provinces and cities in China. Traditional culturable techniques were employed to investigate the community composition and diversity characteristics of culturable soil fungi in different urban habitats. Additionally, FUNGuild was utilized to analyze the ecological functional groups of fungi in these habitats and their functions related to potassium solubilization, phosphorus resolution, nitrogen fixation, and keratin degradation were annotated. In total, 9 779 fungal isolates were screened from the 240 soil samples encompassing 3 phyla (Ascomycota, Basidiomycota, and Mucoromycota), 14 classes, 44 orders, 101 families, 250 genera, and 582 species. The α-diversity analysis of culturable fungal communities revealed significant differences among the different soil habitats. The α-diversity in the green spaces of sewage treatment plants was the highest, and that in zoo green spaces, hospital green spaces, and agricultural land subordinate. Zoo and hospital green spaces exhibited abundant and diverse populations of keratin-degrading fungi. This study provides key information for future management of urban soil microbial resources.
Rhododendron aureum is one of the dominant plants in the tundra belt of Changbai Mountain Nature Reserve. In order to adapt itself to the environmental conditions of infertile soil and cold climate in the tundra of the mountains, R. aureum evolves a special ericoid mycorrhiza (ERM) with some soil fungi, which plays a key ecological role in the plant survival and propagation. Two isolates of ERM fungi were screened from the roots of R. aureum in the tundra of Changbai Mountains, and they were identified as Hyaloscypha hepaticicola by morphological observation and ITS sequence analysis. The study of the biological characteristics showed that the optimum culture conditions for this fungus were as follows: using glucose as carbon source and yeast powder as nitrogen source; cultivation at temperature of 20 ℃ and pH value of 4 under dark condition. This ERM fungus has adopted well to the relatively low temperature and acidic soil environment of the tundra of Changbai Mountains. Further in-depth investigation and economical utilization of H. hepaticicola and other related ERM fungi will be continued.
Pseudobulbs of Cremastra appendiculata have been used as precious and rare traditional Chinese medicine. C. appendiculata seed germination depends on mycorrhizal fungi because of lacking endosperm in tiny dust-like seeds under natural conditions. A symbiotic fungus isolate DJL1 obtained from the roots of C. appendiculata was identified as Coprinellus disseminatus on the basis of morphological and molecular biological characteristics. The results of studies of the biological characteristics showed that the optimum carbon source for the mycelial growth of C. disseminatus were soluble starch, the optimum nitrogen source was yeast extract, the optimum pH was 7.0 and the optimum temperature was 25 ℃. This study was expected to be helpful to the future protection and utilization of C. disseminatus.
Spinach root rot disease was found in five counties of Shandong Province. The roots of the diseased plants turn brown and become shorter, and the root epidermis turns wet rot and vascular bundles are necrotic; the lateral roots are significantly reduced, and the overground parts wilt and green-lose, and finally die in severe cases. Six oomycete strains were isolated and purified by the methods of tissue separation and glass capillary separation, respectively. According to morphological characteristics, biological characteristics, sequence analyses of ITS, cox1 and cox2 together with pathogenicity test by Koch’s postulates, the pathogens were identified as Globisporangium irregulare and G. sylvaticum. This is the first report of spinach root rot caused by G. sylvaticum.
Fruiting body development of Pleurotus ostreatus is a complex biological process regulated by genes in vivo and influenced by various external environmental factors. Aldo-keto reductases (AKR) play important roles in growth and development and stress responses in organisms. In this study, the role of an akr gene during mycelial growth and fruiting body development in P. ostreatus was revealed. The akr RNA interference strains were constructed by Agrobacterium tumefaciens-mediated transformation method, and the effects of akr gene on the mycelial growth rate, heat stress response, and fruiting body development of P. ostreatus were studied. The results showed that, compared with the wild type, the growth rates of the interference strains were significantly reduced during culturing at optimum temperature, heat shock condition and recovery period. The formation time of the primordia was prolonged considerably. These results revealed that akr gene promoted mycelia growth at normal and high temperature, and primordium formation.
Minocycline (MIN), a type of tetracycline used as an antibiotic, is utilized for treatment of various infectious ailments. A previous investigation of ours demonstrated that when minocycline was combined with azoles, it exhibited antifungal properties against Aspergillus fumigatus. Ergosterol is an important component of the fungal cell membrane, and the ERG3 gene encodes a key enzyme for the late stages of the ergosterol synthesis pathway (sterol Δ5,6-desaturase). In this research the ΔERG3 mutant was obtained by knocking out the ERG3 gene of A. fumigatus. The M38 A2 method was used to detect the sensitivity changes of ΔERG3 and wild-type WT (ΔKU80, pyrG+) in combination of MIN and azoles [posaconazole (POS), and itraconazole (ITR), and voriconazole (VOR)] against Aspergillus fumigatus. The results showed that when MIN and POS were combined, the minimum inhibitory concentration (MIC) value of POS against WT was 0.031 25 µg/mL, and the fractional inhibitory concentration index (FICI) value was 0.187 5, indicating a synergistic effect between MIN and POS. The MIC value and FICI value of POS for the knockout strain ΔERG3 were 1 µg/mL and 2, respectively. MIN and POS showed no synergistic effect. The results of the paper method indicate that the diameter of the inhibition zone of ΔERG3 in the combination treatment group (MIN+POS) or single drug treatment group (POS) is significantly smaller as compared with the inhibition zone generated by WT, showing statistically significant difference (P<0.05). This implies that eliminating ERG3 gene could reduce the synergistic effect between MIN and POS. No significant distinction in ergosterol production was observed between WT treated by combination of POS and MIN, and that singly treated by POS. However, a marked decrease in ergosterol production was observed in ΔERG3 under combined treatment of POS and MIN (P<0.05). Reactive oxygen species (ROS) production by ΔERG3 was significantly less than that by WT under monotherapy of POS or combination of POS+MIN. Therefore, ERG3 participates in the synergistic effect pathway of MIN and azole drugs against A. fumigatus. This study provides a new theoretical basis for investigating the mechanism of the synergistic antifungal effect under combination of minocycline and azoles.
Promoters are essential for gene expression strength as functional elements involved in gene expression and regulation. In this study, the endogenous ras promoter of Volvariella volvacea was cloned and identified, analyzed for biosignatures and compared with the exogenous PtrpC promoter-driven catalase (CAT) gene expression efficiency, CAT enzyme activity, antioxidant enzyme gene expression and mycelial physiological traits. The results showed that the ras promoter obtained by cloning had 98.14% sequence similarity to the reported ras sequence; the ras promoter had multiple cis-acting elements such as CAAT-box, TATA-box, G-box, and multiple transcription factor binding sites; compared with the exogenous PtrpC promoter, the endogenous ras promoter-driven target genes cat2 expression and CAT enzyme activity were increased by 262%-407% and 38%-73%, respectively. In addition, the ras-cat2 transformants showed significantly higher antioxidant enzyme gene expression than the PtrpC-cat2 transformants, and the mycelial growth rate and mycelial biomass were increased by 30.15%-44.13% and 19.67%-54.04%, respectively as compared with those of the PtrpC-cat2 transformants, indicating that ras-cat2 transformants showed significantly higher antioxidant enzyme gene expression than PtrpC-cat2 transformants. The fact proves that the ras promoter of V. volvacea has high promoter activity.
Based on morphological and molecular identification, a wild fungal strain LQQ2019129 with brown fruiting bodies collected from the Qilian Mountains was identified as Agaricus bisporus. The effects of different factors on mycelial growth were explored through single factor experiments, and the optimal culture medium formula for domestication and cultivation was optimized through orthogonal experiments. The results showed that, the optimal temperature for mycelial growth is 28 ℃, the optimal carbon source is sucrose, the optimal nitrogen source is yeast powder, the optimal inorganic salt is calcium sulfate, and the optimal calcium sulfate concentration is 1.6 g/L; the optimal medium formula is potato 200 g/L, sucrose 15 g/L, yeast powder 4 g/L, calcium sulfate 1.6 g/L, water 1 000 mL. Under natural pH, the mushroom can produce fruiting body on both wheat straw and corn straw as cultivation substrate, with optimal inoculation amount of 5% for wheat straw and 10% for corn straw. Wheat straw is more suitable than corn straw.
Whole genome re-sequencing of 56 collected Lentinula edodes germplasm resources was performed and their genetic diversity was analyzed. Agronomic traits of the strains were determined, including the mycelial growth rate, cap diameter, cap thickness, stipe diameter, stipe length, single fruit body weight, yield, and cap firmness under factory cultivation conditions. Tested strains were divided into 5 groups according to the systematic clustering and population structure analysis based on SNP molecular markers. It was found that the genetic distance between cultivated and wild strains was relatively far, and there were significant differences in agronomic traits among different groups. Grey correlation analysis was used to comprehensively evaluate the agronomic traits of the fruiting bodies of 43 fructiferous strains. Two strains suitable for industrial cultivation were selected. Further efforts for breeding excellent L. edodes varieties for industrial cultivation are needful.
Headspace solid phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with electronic nose was applied for analysing the flavor substances of fruiting bodies of 9 different strains of Morchella in Ningxia region. A total of 82 volatile compounds was successfully identified, of which 22 volatile components were common to all the samples. From the perspective of overall odor perception, electronic nose could quickly and effectively distinguish the volatile flavor of fruiting bodies of different strains of Morchella. In the 9 samples, there are 18 flavor compounds with a relative odor activity value (ROAV) greater than 0.1. Among them, trans-2-octen-1-ol made the greatest contribution to the flavor of experimental samples 013 and 105, with citrus and fatty flavors. Isovaleraldehyde made the greatest contribution to the flavor of samples 159, 196, HLGO, SB25C, and Y1 (1719), with malty and fruity flavors. 2(5H)-furanone greatly contributed to the flavor of samples 166 and LY, with nutty and coconut flavors. Based on principal component analysis (PCA) of these 18 flavor substances, a comprehensive function quality evaluation model was established. It was found that the strain 105 had the highest score, indicating that it had the best flavor quality.
High energy consumption and quality deterioration caused by low drying efficiency are serious challenges faced by the dry processing of Tremella fuciformis. In order to improve their drying characteristics, T. fuciformis fruiting bodies were pretreated with low-voltage electrostatic field (LVEF) before separately undergoing drying processes by solar energy-heat pump, and hot air as well as the microwave vacuum drying. The moisture state and distribution of fresh fruiting bodies in the pretreatment process as well as the shrinkage, rehydration ratio, crude polysaccharide, soluble protein, color and antioxidant property of dried fruiting bodies were determined. It was found that with the increase of the pretreatment time (0-48 h) in the low voltage electrostatic field, the original dominant water in the fruiting bodies, which was not easy to flow, was gradually changed to free water, and the water gradually migrated from the base to the lobes. Compared with the unpretreated group, the shrinkage of the solar energy-heat drying pump pretreatment group was reduced by 18.13%, and the rehydration ratio and crude polysaccharide content were increased by 19.28% and 11.24%, respectively. The soluble protein content and DPPH radical scavenging rate of the hot air-drying pretreatment group increased by 17.96% and 19.34%, respectively. The ABTS radical and hydroxyl radical scavenging rate of the microwave vacuum drying pretreatment group increased by 9.32% and 25.29%, respectively. The hot air-dried samples was darker-colored and most seriously browning, but the low voltage electrostatic field pretreatment could better maintain the color of the dried fruiting bodies. The volatile flavor components of dried fruiting bodies were mainly dominated by inorganic sulfides, aromatic and methyl compounds. The low-voltage electrostatic field pretreatment is conducive to enhance the texture and taste quality of the boiled T. fuciformis, making it better adhesiveness and tenacity.
