Umbelopsis dimorpha sp. nov., a link between U. vinacea and U. versiformis

Three new compounds of Umbelopsis dimorpha VDG10, a dominant endophytic fungus from Vaccinium dunalianum Wight

Three novel compounds, including an aromatic amino acid, dimorine A (1), a suncheonoside derivative, dimoroside A (2), and a phenylpropanoid glycoside, dimoroside B (3), together with four known compounds (4-7) were separated from Umbelopsis dimorpha VDG10, the predominant endophytic fungus found in the roots of Vaccinium dunalianum Wight (Ericaceae). Their structures were elucidated by spectroscopic methods, and the ECD spectrum confirmed the absolute configuration of 3. In addition, the antifungal activities of novel compounds against five phytopathogenic fungi were evaluated. The results indicated that compound 3 has a better inhibitory effect on Alternaria brassicicola than the broad-spectrum antifungal agent thiabendazole, and its MICs of 15.63-7.82 μg/mL.

Molecular phylogenetics of the Umbelopsis genus-identification of new species and evaluation of their oil application value

AIMS

The aim of this study was to reconstruct the evolutionary framework of the genus Umbelopsis by using modern taxonomic strategies and evaluating the quality of oil and prospective uses of three distinct species.

METHODS AND RESULTS

Three species of Umbelopsis were identified based on morphological characteristics and phylogenetic evidence obtained from three genes (ITS, LSU, and ACT). A new species of Umbelopsis was described and illustrated, and subsequently named U. ophiocordycipiticola. The characteristics of U. ophiocordycipiticola exhibited sporangia with a diameter ranging from 8 to 17 µm. and sporangiospores that were oval to ellipsoidal in shape, irregularly angular, with dimensions of ∼1.9-2.9 × 1.7-3.0 µm. Gas chromatography and mass spectrometry (GC-MS) were used to examine the composition of fatty acids. Notably, U. ophiocordycipiticola showed a significantly higher oil content of 50.89% in dry cell weight (DCW) compared to U. vinacea and U. ramanniana. The mean proportion of polyunsaturated fatty acids (PUFAs) in U. ophiocordycipiticola was 32.38%, and the maximum levels of γ-linolenic acid (GLA), arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) in U. ophiocordycipiticola were found to be 14.51, 0.24, 0.54, and 0.53%, respectively. The biodiesel quality from all three species complied with applicable standards set by the American Association for Testing and Materials (ASTM 6751) and the Brazilian National Petroleum Agency (ANP 255).

CONCLUSIONS

The establishment of a novel species, U. ophiocordycipiticola, was strongly supported by morphological and molecular evidence. Umbelopsis ophiocordycipiticola exhibited a high-value PUFA content. Additionally, three Umbelopsis species demonstrated good quality for biodiesel production.

The Umbelopsis ramanniana Sensu Lato Consists of Five Cryptic Species

Umbelopsis ramanniana is one of the most commonly reported species within the genus and an important oleaginous fungus. The morphology of the species varies remarkably in sporangiospores, columellae and chlamydospores. However, phylogenetic analyses based on ITS and nLSU rDNA had previously shown insufficiency in achieving species level identification in the genus Umbelopsis. In this study, by applying a polyphasic approach involving multi-gene (nSSU, ITS, nLSU, act1, MCM7 and cox1) phylogeny, morphology and maximum growth temperature, U. ramanniana sensu lato was revealed as a polyphyletic group and resolved with five novel taxa, namely U. curvata, U. dura, U. macrospora, U. microsporangia and U. oblongielliptica. Additionally, a key for all currently accepted species in Umbelopsis was also updated.

Effects of an Endophytic Fungus Umbelopsis dimorpha on the Secondary Metabolites of Host-Plant Kadsura angustifolia

Fungal endophytes live widely inside plant tissues and some have been revealed to provide benefits to their host and ecological environment. Considering the fact that endophytes are engaged in remarkably stable long-term interactions with the host for their whole life cycle, it's conceivable that both partners have substantial influence on each other's metabolic processes. Here, we investigated the fermented products of an endophytic fungus Umbelopsis dimorpha SWUKD3.1410 grown on host-plant Kadsura angustifolia and wheat bran, respectively, to assess the impact of SWUKD3.1410 on the secondary metabolites of K. angustifolia. Twenty compounds (1-20) were isolated and identified as 11 schitriterpenoids (1-9, 17-18), two lignans (10, 20), two sesquiterpenoids (11-12), one trinorsesquiterpenoid (13), one monoterpene (14), one sterol (19), and two simple aromatic compounds (15-16) by the extensive 1D-, 2D-NMR and HR-ESI-MS data analysis. Except for nigranoic acid (1), compounds 2-19 have been firstly found from K. angustifolia. Of them, metabolites 2, 11, and 14 were identified to be new. Obtained results indicated that U. dimorpha SWUKD3.1410 could not only produce the same/similar components as its host does, and modify the host-plant components, but also enhance the production of these highly oxygenated schitriterpenoids/schinortriterpenoids in plants. This study suggested an interesting prospective for setting up alternative processing techniques to improve the quality of crude drugs derived from K. angustifolia and increase their values.

Umbelopsis longicollis comb. nov. and the synonymy of U. roseonana and U. versiformis with U. nana

Based on maximum growth temperatures, morphological characteristics and multilocus phylogenies (partial 18S and 28S, internal transcribed spacer regions of nuc rDNA and a fragment of an actin gene), Umbelopsis roseonana and U. versiformis are treated as heterotypic synonyms of U. nana, while the phylogenetically closely related U. dimorpha is retained as a separate species. Mortierella longicollis is reclassified as a new combination, U. longicollis. In addition, lectotypes and epitypes for the basionyms of U. longicollis and U. nana are designated here.

Four New Species Records of Umbelopsis (Mucoromycotina) from China

Four species of Umbelopsis newly found in China, that is, U. angularis, U. dimorpha, U. nana, and U. versiformis, are reported in this paper. Descriptions and illustrations are provided for each of them.