Mycobiology最新文献

Chytridiomycota is the most species-rich phylum of basal lineage fungi with a worldwide distribution. Its species constitute essential components of freshwater ecosystems. However, the diversity of this group in Korea remains understudied. A survey of Chytridiales and Rhizophydiales fungi was conducted in soil and freshwater environments in Korea, and seven strains were isolated. Based on morphological and molecular data, a previously unidentified, novel Rhizophydium species was discovered, designated Rhizophydium multiplex sp. nov. In addition, Chytriomyces hyalinus and Globomyces pollinis-pini were isolated for the first time in Korea. Detailed descriptions and illustrations of the three species are provided. This study highlights the potential diversity of chytrid fungi in Korea.

Garlic (Allium sativum) is an indispensable ingredient for enriching and diversifying Indonesian cuisine taste. Indonesian people always use garlic for their daily dishes and any traditional foods. Due to its widespread culinary use, its availability in the market become critical. The main challenge to consistently growing this garlic is Fusarium oxysporum f. sp. cepae, which wilts Allium plants. The application of arbuscular mycorrhiza fungi (AMF) + Bacillus amyloliquefaciens B1 on local garlic varieties named Lumbu Hijau could effectively control F. oxysporum through in vitro and in vivo experiments. In the in vitro test, B. amyloliquefaciens B1 successfully suppressed the growth of F. oxysporum up to 53.41%. The consortium application in the greenhouse reduced disease incidence by up to 39.17%, and the efficacy of this biocontrol reached 84%. In addition, this approach also positively influenced plant growth, such as plant height, total wet shoot and root weight, and also tuber weight. As such, it is essential to use this consortium of microorganisms in field research and carry out a comprehensive investigation to identify any possible phenomena that may arise in the rhizosphere after application.

Laccases are enzymes capable of oxidizing phenolic compounds and are important tools in different industrial processes. Heterologous expression of laccases is of great interest in biotechnological applications but achieving high expression levels is challenging. Three different laccases have been identified in the chestnut blight fungus Cryphonectria parasitica, among which a tannic acid-inducible laccase (laccase3) was successfully expressed using Saccharomyces cerevisiae. To obtain high and stable expression of fungal laccases, we cloned the gene encoding an extracellular laccase (Laccase1) of C. parasitica into a yeast episomal vector, used the resulting vectors to transform S. cerevisiae, and optimized the culture conditions of the selected transformants for Laccase1 production. We also tested the significance of the signal peptide of Laccase1 in the secretion of expressed Laccase1 and compared it with the widely used rice amylase signal peptide. Among the four constructs tested using a yeast episomal vector, full-length Laccase1 containing an endogenous signal peptide, showed the highest laccase activity. Interestingly, the stability of the recombinant vector expressing laccase was lower than that of the mock transformant, suggesting a detrimental effect of the Laccase1-expressing vector on host cells. Thus, we optimized the culture conditions to produce Laccase1 and the resulting optimum culture conditions identified through one-factor-at-a -time (OFAT) were 2% sucrose; 3% yeast nitrogen base without amino acid; pH 5.0; and 30 °C. The laccase activity was found to be 2.2 U/mL in optimal culture conditions, resulting in a 6.5-fold increase compared to the conventional culture medium.

The exploration of endophytic fungi associated with seaweeds has garnered significant interest due to their crucial ecological functions and potential as sources of valuable bioactive compounds. In this study, we isolated and identified endophytic fungi from the brown seaweed Dictyopteris pacifica, collected from the intertidal zone of Yeongdoek, Gyeongsangbuk-do in Korea. Through morphological examination and molecular phylogenetic analysis using multiple molecular markers, including ITS, LSU, SSU, TEF1, TUB2, and RPB2 sequences, we identified three fungal species not previously recorded in Korea: Emericellopsis fuci, Neoarthrinium lithocarpicola, and Periconia chimonanthi. Detailed descriptions of morphological characteristics and phylogenetic analyses are provided. This study represents the first report of these endophytic fungi isolated from D. pacifica in Korea, thereby enhancing the understanding of the diversity of seaweed-associated endophytic fungi in the region.

During an investigation of fungi of the orders Mucorales and Mortierellales in Korea, a new Backusella species, Backusella terrestris sp. nov., and three new records, Entomortierella sugadairana, Mucor nederlandicus, and Poitrasia circinans, were found in soil and freshwater samples. All species are described based on morphological and molecular evidence. Backusella terrestris is characterized by globose or subglobose sporangiospores, a variable (globose, subglobose, oval, or oblong) columellae, chlamydospore production, and a maximum growth temperature of 34 °C. The distinct characteristics of the new species and their closely related species are discussed. An identification key to the Backusella species of Korea is also presented.

During the collection of macrofungi resources in Son Tra Nature Reserve, Danang, Vietnam, two fungal specimens of the genus Anthracophyllum, designated as M34295 and M3457, living on dead still-attached branches of Mussaenda frondosa L. at an elevation around 360 m above the sea level were recorded. The morphological characteristics of the specimens shared some common characteristics with Anthracophyllum spp. However, the specimens possessed some distinct characteristics from other Anthracophylllum species. The phylogenetic analyses based on the combined internal transcribed spacer (ITS) and Large Subunit (LSU) molecular markers of ribosomal RNA genes revealed that the two specimens clustered in a single clade at species level with all tested Anthracophyllum species with strong bootstrap support of 99%. Among Anthracophyllum genus, our specimens seemed closest to A. archeri in morphological and genetic characteristics. Based on the combination of morphological approaches and multilocus phylogenetic analyses, we introduced Anthracophyllum sontraense sp. nov. as a new species. A. sontraense was characterized by its skewed bell-like basidiome with the color of dark blue to midnight blue, 1.0 - 1.5 cm diam, stipeless, light pink lamellae, sparse, occasionally branching. Basidiospores broadly ovoid to subglobose, 6-7 × 5.5-6 µm. To our knowledge, this is the first record of Anthracophyllum fungus in Vietnam.

Endophytic fungi associated with four plant species in Korea were isolated and characterized using morphological and molecular analyses. Phylogenetic analyses of the internal transcribed spacer (ITS) region, β-tubulin (TUB) gene, and translation elongation factor 1-α (EF1-α) gene revealed four previously unrecorded species of Diaporthe in Korea: D. caryae, D. phoenicicola, D. stewartii, and D. unshiuensis. Detailed descriptions of colony morphology and conidial characteristics are provided for each species. This study expands our knowledge of the diversity and distribution of endophytic Diaporthe in Korea and highlights the importance of these fungi in the ecosystem.

During disease surveys in 2021 and 2022, outbreaks of leaf spot were observed in East Asian hogweed (Heracleum moellendorffii) plants in fields located in Pyeongchang and Yeongwol, Gangwon Province, Korea. The disease incidence in the fields ranged from 2% to 50%. Based on the morphological and cultural characteristics, four single-conidium fungal isolates from the leaf spot symptoms were identified as Phoma sp. The phylogenetic analyses based on the combined sequences from the four genes (LSU, ITS, TUB2, and RPB2) indicated that the isolates clustered very closely with Didymella acutilobae. However, the morphological and cultural characteristics of the isolates exhibited somewhat distinct differences from those of D. acutilobae, suggesting that the isolates correspond to a novel subspecies. Pathogenicity tests revealed that the isolates caused leaf spot in East Asian hogweed plants. This is the first report of D. acutilobae subsp. heraclei subsp. nov. causing leaf spot in East Asian hogweed.

Food insecurity and malnutrition are among the major problems in most developing nations recently. Mushroom cultivation is one of the promising strategies to overcome these challenges. The growth and productivity of mushrooms differ because of their wide range of cultivation substrates. Cultivating Pleurotus ostreatus on suitable substrates is one of the key factors affecting its growth and productivity. This study was, therefore, conducted to investigate the effect of cultivation substrates, namely straws of tef (Trt1), barley (Trt2), and wheat (Trt3), husks of faba bean (Trt4) and field pea (Trt5), and sawdust (Trt6) alone, and their mixture (1:1, w/w) (Trt7) on the growth and yield of P. ostreatus. Mycelial colonization, primordial formation, and days to first harvest were faster (13.00, 19.67, and 22.67 days) for the P. ostreatus cultivated on Trt7 whereas those grown on Trt6 were delayed (18.00, 27.00, and 29.67 days), respectively. Trt7 gave a higher (67.33) fruiting body/bunch and total yield (2001.70 g/bag). Biological efficiency was also significantly (p < 0.05) higher for Trt7 (238.64%). Strong relationships between cap diameter and mushroom yield (r = 0.84***), number of bunches (r = 0.76***), number of fruiting bodies (r = 0.80***), stipe length (r = 0.83***), and total yield (r = 0.84***) were among significant positive correlations observed. In conclusion, cultivating P. ostreatus on the Trt7 (mixed substrate) is recommended rather than using either of the residues alone.

The cultivation period of shiitake (Lentinula edodes) is approximately 120-150 d, which is longer than that of other edible mushrooms. The development of fruiting bodies in shiitake is affected by light exposure. In this study, we investigated the effects of blue light on the production and ergothioneine contents of shiitake mushrooms. Fruiting body production (yield) on the medium irradiated with blue light increased in both cultivars (L808, 555 ± 60 g/3 kg medium; Sanbackhyang, 1090 ± 106 g/3 kg medium). Additionally, blue light increased the ergothioneine contents and antioxidative activities, and the ergothioneine content of L808 (about 2.8 mg/g) was higher than that of Sanbackhyang (about 1.2 mg/g). These results suggest that blue light is effective in shortening the cultivation period and increasing ergothioneine contents during shiitake cultivation.