This article is the 13th contribution in the Fungal Diversity Notes series, wherein 125 taxa from four phyla, ten classes, 31 orders, 69 families, 92 genera and three genera incertae sedis are treated, demonstrating worldwide and geographic distribution. Fungal taxa described and illustrated in the present study include three new genera, 69 new species, one new combination, one reference specimen and 51 new records on new hosts and new geographical distributions. Three new genera, Cylindrotorula ( Torulaceae ), Scolecoleotia ( Leotiales genus incertae sedis ) and Xenovaginatispora ( Lindomycetaceae ) are introduced based on distinct phylogenetic lineages and unique morphologies. Newly described species are Aspergillus lannaensis , Cercophora dulciaquae , Cladophialophora aquatica , Coprinellus punjabensis , Cortinarius alutarius , C. mammillatus , C. quercoflocculosus , Coryneum fagi , Cruentomycena uttarakhandina , Cryptocoryneum rosae , Cyathus uniperidiolus , Cylindrotorula indica , Diaporthe chamaeropicola , Didymella azollae , Diplodia alanphillipsii , Dothiora coronicola , Efibula rodriguezarmasiae , Erysiphe salicicola , Fusarium queenslandicum , Geastrum gorgonicum , G. hansagiense , Helicosporium sexualis , Helminthosporium chiangraiensis , Hongkongmyces kokensis , Hydrophilomyces hydraenae , Hygrocybe boertmannii , Hyphoderma australosetigerum , Hyphodontia yunnanensis , Khaleijomyces umikazeana , Laboulbenia divisa , Laboulbenia triarthronis , Laccaria populina , Lactarius pallidozonarius , Lepidosphaeria strobelii , Longipedicellata megafusiformis , Lophiotrema lincangensis , Marasmius benghalensis , M. jinfoshanensis , M. subtropicus , Mariannaea camelliae , Melanographium smilaxii , Microbotryum polycnemoides , Mimeomyces digitatus , Minutisphaera thailandensis , Mortierella solitaria , ...

Deadwood decomposition is relevant in nature and wood inhabiting fungi (WIF) are its main decomposers. However, climate influence on WIF community and their interactions with bacteria are poorly understood. Therefore, we set up an in-field mesocosm experiment in the Italian Alps and monitored the effect of slope exposure (north- vs. south-facing slope) on the decomposition of Picea abies wood blocks and their microbiome over two years. Unlike fungal richness and diversity, we observed compositional and functional differences in the WIF communities as a function of exposure. Wood-degrading operational taxonomic units (OTUs) such as Mycena, and mycorrhizal and endophytic OTUs were characteristic of the south-facing slope. On the north-facing one, Mucoromycota, primarily Mucor, were abundant and mixotrophic basidiomycetes with limited lignin-degrading capacities had a higher prevalence compared to the southern slope. The colder, more humid conditions and prolonged snow-coverage at north exposure likely influenced the development of the wood-degrading microbial communities. Networks between WIF and N2-fixing bacteria were composed of higher numbers of interacting microbial units and showed denser connections at the south-facing slope. The association of WIF to N2-fixing Burkholderiales and Rhizobiales could have provided additional competitive advantages, especially for early wood colonization.

Cultivation of undescribed rumen microorganisms is one of the most important tasks in rumen microbiology. In this study, we aimed to discover the potential of culturomics for characterizing the rumen microbiome and for identifying factors, specifically sample dilution and media type, which affect microbial richness on agar plates. Our cultivation experiment captured 23% of all operational taxonomic units (OTUs) found in the rumen microbiome in this study. The use of different media increased the number of cultured OTUs by up to 40%. Sample dilution had the strongest effect on increasing richness on the plates, while abundance and phylogeny were the main factors determining cultivability of rumen microbes. Our findings from phylogenetic analysis of cultured OTUs on the lower branches of the phylogenetic tree suggest that multifactorial traits govern cultivability. Interestingly, most of our cultured OTUs belonged to the rare rumen biosphere. These cultured OTUs could not be detected in the rumen microbiome, even when we surveyed it across a 38 rumen microbiome samples. These findings add another unique dimension to the complexity of the rumen microbiome and suggest that a large number of different organisms can be cultured in a single cultivation effort.

Background Metagenomic sequencing has led to the identification and assembly of many new bacterial genome sequences. These bacteria often contain plasmids: usually small, circular double-stranded DNA molecules that may transfer across bacterial species and confer antibiotic resistance. These plasmids are generally less studied and understood than their bacterial hosts. Part of the reason for this is insufficient computational tools enabling the analysis of plasmids in metagenomic samples. Results We developed SCAPP (Sequence Contents-Aware Plasmid Peeler)—an algorithm and tool to assemble plasmid sequences from metagenomic sequencing. SCAPP builds on some key ideas from the Recycler algorithm while improving plasmid assemblies by integrating biological knowledge about plasmids. We compared the performance of SCAPP to Recycler and metaplasmidSPAdes on simulated metagenomes, real human gut microbiome samples, and a human gut plasmidome dataset that we generated. We also created plasmidome and metagenome data from the same cow rumen sample and used the parallel sequencing data to create a novel assessment procedure. Overall, SCAPP outperformed Recycler and metaplasmidSPAdes across this wide range of datasets. Conclusions SCAPP is an easy to use Python package that enables the assembly of full plasmid sequences from metagenomic samples. It outperformed existing metagenomic plasmid assemblers in most cases and assembled novel and clinically relevant plasmids in samples we generated such as a human gut plasmidome. SCAPP is open-source software available from: https://github.com/Shamir-Lab/SCAPP.

Deadwood decay employs a complex metabolism and provides carbon and nutrients for soils. Although being highly diverse, the contribution of the bacterial deadwood colonizing community is underexplored compared with the fungal one. Therefore, we performed an in-field mesocosm study and monitored the bacterial communities in decaying experimental Picea abies wood blocks and their underlying soil on north- and south- exposed slopes in the Italian Alps over a 2-year period. The faster deadwood decay at the south-facing slope was associated with a higher bacterial richness and a higher number of specialist operational taxonomic units (OTUs) which were more strongly correlated to environmental parameters than other bacterial community members. With progressing decay, the wood and soil bacterial communities became more similar in terms of richness, diversity and evenness and especially at the south-facing slope, they also became more similar in terms of community composition. Exposure-specific OTUs suggest wood-soil interaction. However, despite the strong influence of exposure on the soil bacterial communities, the P. abies wood blocks shared a comparably high number of OTUs with the soil irrespective of the slope. At finer taxonomic scale, we identified Pseudomonas, Microbacteria, Sphingomonas, Xanthomonas, Methylovirgula and Burkholderia as decay associated, although their functional role needs further studies.

Mortierellaceae species are among the most frequent and globally distributed soil fungi. However, the factors shaping their diversity and distribution remain obscure. Several species have been reported to be associated to bacteria, but the kind and frequency of such associations were not addressed up to now. We hypothesized that such associations could be important for Mortierellaceae ecology. Therefore, our aim was to understand the driving factors responsible for the Mortierellaceae diversity, community composition and bacterial associations in alpine and subalpine habitats. For answering our question, we collected both snow-free and snow-covered soil at sampling sites from different habitats: bare alpine soil in a glacier forefield, alpine dwarf-willow habitats, and high-altitude Pinus cembra forests. The isolations were carried out by direct cultivation without any antibiotics to the isolation media. Altogether, we obtained 389 Mortierellaceae isolates representing 29 operational taxonomic units (OTUs). Many OTUs could be placed to the genera Mortierella sensu stricto, Dissophora, Entomortierella, Gamsiella, Linnemannia, and Podila, but others could not unambiguously be assigned to a genus. Our results demonstrate that both, the distribution as well as the diversity of the Mortierellaceae species, were significantly influenced by habitat, soil pH, and snow-cover. We noticed that >30% of our isolates were associated to a non-contaminant bacterium. The bacteria associated to our Mortierellaceae isolates belonged to seven different genera. Pseudomonas was the most frequently detected genus associated to the isolated Mortierellaceae species and it was found to be species-specific. Mortierellaceae–bacteria pairs, including those with Pseudomonas, were influenced by location, habitat, and snow-cover. The majority of the fungus–bacterium associations were potentially epihyphal, but we also detected potential endohyphal bacterial species belonging to Mycoavidus, Burkholderiaceae, and Paraburkholderia. Taken together, the non-random associations we detected suggest that fungus–bacterium associations are ecologically meaningful – an interesting path that needs to be investigated further.

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