Triangularia mangenotti was analyzed for the production of secondary metabolites, resulting in the isolation of known zopfinol (1) and its new derivatives zopfinol B–C (2–4), the 10-membered lactones 7-O-acetylmultiplolide A (5) and 8-O-acetylmultiplolide A (6), together with sordarin (7), sordarin B (8), and hypoxysordarin (9). The absolute configuration of 1 was elucidated by the synthesis of MPTA-esters. Compound 1 showed antimicrobial activity against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus and the fungus Mucor hiemalis. While 4 was weakly antibacterial, 3 showed stronger antibiotic activity against the Gram-positive bacteria and weak antifungal activity against M. hiemalis and Rhodotorula glutinis. We furthermore observed the cytotoxicity of 1, 3 and 4 against the mammalian cell lines KB3.1 and L929. Moreover, the new genus Pseudorhypophila is introduced herein to accommodate Triangularia mangenotii together with several species of Zopfiella—Z. marina, Z. pilifera, and Z. submersa. These taxa formed a well-supported monophyletic clade in the recently introduced family Navicularisporaceae, located far from the type species of the respective original genera, in a phylogram based on the combined dataset sequences of the internal transcribed spacer region (ITS), the nuclear rDNA large subunit (LSU), and fragments of the ribosomal polymerase II subunit 2 (rpb2) and β-tubulin (tub2) genes. Zopfiella submersa is synonymized with P. marina due to the phylogenetic and morphological similarity. The isolation of zopfinols 1–4 and sordarins 7–9 confirms the potential of this fungal order as producers of bioactive compounds and suggests these compounds as potential chemotaxonomic markers.

Novel species of fungi described in this study include those from various countries as follows: Argentina, Septoria reinamora on leaf spots of Mutisia spinosa. Australia, Cortinarius albofolliculus on mossy soil, Cortinarius descensoriformis among leaf litter, Cortinarius kaki among leaf litter, Cortinarius lissosporus in leaf litter, Cortinarius malogranatus in leaf litter, Cortinarius meletlac on soil in mixed forest, Cortinarius sebosioides in long decayed wood litter, Helicogermslita australiensis as an endophyte from healthy leaves of Archontophoenix cunninghamiana, Puccinia clemensiorum on culms of Eleocharis ochrostachys, Puccinia geethae on leaves of Cyperus brevifolius, Puccinia marjaniae on leaves of Nymphoides indica, Puccinia scleriae-rugosae on leaves of Scleria rugosa. Brazil, Dactylaria calliandrae on living leaf of Calliandra tweediei, Mucor cerradoensis from soil, Musicillium palmae on living leaves of unidentified palm species, Neodendryphiella agapanthi from stalks of Agapanthus praecox, Parafusicladium riodejaneiroanum on living leaves of native bamboo, Parapenidiella melastomatis on living leaves of unidentified Melastomataceae, Pararamichloridium ouropretoense on living leaves of unidentified Poaceae, Pentagonomyces endophyticus (incl. Pentagonomyces gen. nov.) as endophytic from roots of Musa acuminata, Polyschema endophytica from healthy roots of coffee plant, Purimyces endophyticus as root endophyte of Cattleya locatellii, Ramularia rhododendri on living leaves of Rhododendron sp., Staphylotrichum soli from soil, Trichoderma sexdentis from leaves inside a nest of the leaf-cutting ant Atta sexdens rubropilosa, Wiesneriomyces soli from soil. France, Cosmospora nemaniae on dead or effete stromata of Nemania cf. colliculosa, Inocybe alnobetulae in subalpine green alder stands, Stylonectria hygrophila on dead twigs of Betula pubescens. Germany, Coniochaeta corticalis from bark humus, Coniochaeta fermentaria from fermentation residues from biogas plants, Coniochaeta fibricola from softwood fibres, Coniochaeta weberae from bark humus, Inocybe canicularis on calcareous to more acidic soil with conifers. Iceland, Inocybe islandica associated with Dryas octopetala. India, Vishniacozyma indica on dead twigs. Iran, Botryotrichum lycii on rotten leaf of Lycium depressum. Italy, Cuphophyllus dolomiticus among Salix retusa, Salix reticulata and Dryas octopetala, Inocybe subentolomospora on moss with the presence of Alnus incana, Populus nigra and Salix spp. Malaysia, Catenulostroma pellitae on leaf spots of Eucalyptus pellita. Mexico, Colletotrichum mexicanus from fruit of Persea americana cv. Hass. New Caledonia (France), Cortinarius caeloculus, Cortinarius luteigemellus and Cortinarius perpensus on soil under Nothofagus aequilateralis. New Zealand, Cytospora braithwaitei on branch of Malus domestica. Pakistan, Callistosporium khalidii on humus soil, Entoloma lilacinum on litter in conifer forest, Laccaria decolorans on litter in broad-leaved subtropical forest. Poland, Pseudoneoconiothyrium modrzynanum from resin of Larix decidua ssp. polonica, Tuberculiforma enigmatica isolated from sooty mould community on Quercus robur leaves. Portugal, Clavulus hemisphaericus (incl. Clavulus gen. nov.) on mossy slopes and under Laurus leaf litter, Entoloma daegae on sandy, granitic soil, Hygrocybe aurantiocitrina under laurel forest, Hygrocybe sanguineolutea gregarious in laurel forest, Hygrocybe vulcanica on mossy areas of laurel forest areas, Pachyphlodes algarvensis on sandy soil under Cistus salvifolius, Quercus suber and Pinus pinea. South Africa, Amycosphaerella podalyriae on leaf of Podalyria calyptrata, Erythrobasidium eucalypti from the gut of Gonipterus sp., Letendraea goniomae on leaves of Gonioma kamassi, Pezicula brabeji and Sphaerulina brabeji on twigs of Brabejum stellatifolium, Stachybotrys conicosiae on dead flower head of Conicosia elongata, Talaromyces ignescens from soil. Spain, Cortinarius phaeobrunneus on soil under Quercus ilex and Q. faginea, Inocybe pini-halepensis among grass and fallen leaves of Pinus halepensis, Inocybe subporcorum in sandy soils under Quercus ilex subsp. ballota and Pinus pinaster, Mycena morenoi on dead leaves of Betula pubescens and Salix atrocinerea, Pachyphlodes iberica on clayey and loamy soil under Quercus ilex and Quercus rotundifolia, Ramariopsis coronata in laurel forest. Switzerland, Inocybe minata in a bog on very wet acidic soil with Salix spp. and Betula spp. Thailand, Hypocrella khonsanitii on scale insects (Coccidae), Petchiella hymenopterorum on hymenopteran pupae in the nest (Hymenoptera). Trinidad and Tobago, Neodevriesia maravalensis from office swab. Türkiye, Russula anatolica under Quercus vulcanica. UK, Paracylindrosporium dactylorhizae (incl. Paracylindrosporium gen. nov.) on leaf spots of Dactylorhiza sp., Niesslia hepworthiae and Niesslia libertiae on living leaves of Libertia grandiflora. Ukraine, Lichenohendersonia cetrariae on thallus of terricolous Cetraria aculeata. USA, Atromagnispora indianensis (incl. Atromagnispora gen. nov.) on submerged wood in a freshwater stream, Cytospora michiganensis from utility room (settle plate), Exophiala aeris from air (settle plate), Hongoboletus americanus from mixed pine-hardwood forest, Lorrainsmithia pennsylvanica from bedroom, air, Superstratomyces massachusettsanus from lyse buffer. Vietnam, Aspergillus halopiscium on dry marine anchovy Stolephorus commersonnii. Morphological and culture characteristics are supported by DNA barcodes.

The new genus Morinagamyces is introduced herein to accommodate the fungus Apiosordaria vermicularis as inferred from a phylogenetic study based on sequences of the internal transcribed spacer region (ITS), the nuclear rDNA large subunit (LSU), and partial fragments of ribosomal polymerase II subunit 2 (rpb2) and β-tubulin (tub2) genes. Morinagamyces vermicularis was analyzed for the production of secondary metabolites, resulting in the isolation of a new depsipeptide named morinagadepsin (1), and the already known chaetone B (3). While the planar structure of 1 was elucidated by extensive 1D- and 2D-NMR analysis and high-resolution mass spectrometry, the absolute configuration of the building blocks Ala, Val, and Leu was determined as -l by Marfey’s method. The configuration of the 3-hydroxy-2-methyldecanyl unit was assigned as 22R,23R by J-based configuration analysis and Mosher’s method after partial hydrolysis of the morinagadepsin to the linear derivative compound 2. Compound 1 showed cytotoxic activity against the mammalian cell lines KB3.1 and L929, but no antimicrobial activity against the fungi and bacteria tested was observed, while 2 was inactive. Compound 3 was weakly cytotoxic against the cell line L929, but did not show any antimicrobial activity.

Streptogramins are the last line of defense antimicrobials with pristinamycin as a representative substance used as therapeutics against highly resistant pathogenic bacteria. However, the emergence of (multi)drug-resistant pathogens renders these valuable antibiotics useless; making it necessary to derivatize compounds for new compound characteristics, which is often difficult by chemical de novo synthesis due to the complex nature of the molecules. An alternative to substance derivatization is mutasynthesis. Herein, we report about a mutasynthesis approach, targeting the phenylglycine (Phg) residue for substance derivatization, a pivotal component of streptogramin antibiotics. Mutasynthesis with halogenated Phg(-like) derivatives altogether led to the production of two new derivatized natural compounds, as there are 6-chloropristinamycin I and 6-fluoropristinamycin I based on LC-MS/MS analysis. 6-Chloropristinamycin I and 6-fluoropristinamycin I were isolated by preparative HPLC, structurally confirmed using NMR spectroscopy and tested for antimicrobial bioactivity. In a whole-cell biotransformation approach using an engineered E. coli BL21(DE3) pET28-hmo/pACYC-bcd-gdh strain, Phg derivatives were generated fermentatively. Supplementation with the E. coli biotransformation fermentation broth containing 4-fluorophenylglycine to the pristinamycin mutasynthesis strain resulted in the production of 6-fluoropristinamycin I, demonstrating an advanced level of mutasynthesis.

Streptomyces sp. DSM 115979T, isolated from soil collected in Lavasan (Iran), was classified as a novel subspecies of Streptomyces barkulensis, for which the name S. barkulensis subsp. lavasanensis subsp. nov. is proposed. Culture extracts yielded lavasamycin A (1) and B (2); their structures were elucidated by comprehensive HR-MS and NMR spectroscopic analyses, revealing a dihydroxyanthraquinone scaffold carrying a previously unreported N-acetyl-didesmethyl analogue of the aminodeoxysugar ossamine. Lavasamycin B (2) additionally features an unusual α,β-unsaturated γ-butenolide moiety. Lavasamycin A (1) exhibited antibacterial activity against Bacillus subtilis. Genome mining and comparative bioinformatic analyses identified the corresponding type II polyketide synthase biosynthetic gene cluster (BGC). Deletion of the ketosynthase genes lav31−lav32 abolished lavasamycin production, confirming the identity of the BGC. Inactivation of the TetR-family regulator gene lav34 resulted in substantially increased lavasamycin production, indicating pathway-specific transcriptional repression. Comparative analyses revealed similarities to angucycline and aminodeoxysugar biosynthetic pathways and enabled the proposal of a biosynthetic route to lavasamycin. In particular, the similarity of Lav15 to UrdM supports A-ring cleavage via Baeyer−Villiger oxidation. A spontaneous autoxidation likely converts 1 into 2. These findings expand the structural diversity of bacterial aromatic polyketides and highlight the biosynthetic potential of newly characterized Streptomyces taxa.

An investigation of coprophilous fungi from Germany resulted in the collection of new species of Scytalidium and Parascedosporium . This latter genus was subjected for the first time to a multilocus analysis based on internal transcribed spacer region (ITS), D1–D3 domains of the nuclear rDNA large subunit (LSU), beta-tubulin ( TUB2 ), and a fragment of calmodulin ( CAL ) corroborating the synonymy of the three species located in the genus, which was performed a long time ago based only on ITS sequences. Moreover, the description of Collariella carteri was emended to include the morphology of a specimen isolated during this study. Collariella carteri was characterized by short and setae-like terminal ascomatal hairs, which was the main characteristic to distinguish it from the closest relatives. However, our isolate presents spirally coiled hairs. The type strain of C. pachypodioides , which is the closest species to C. carteri was also studied, and a modern description and illustrations are here provided for the first time since this species was described in 1945. The delimitation of both species needs to be done by using molecular data due to the absence of morphological differences between them.