Search

Heat resistance is the ability to survive short, extreme temperature stresses, exceeding the own growth temperature by far. Despite their occurrence in natural substrates and their relevance for the food and healthcare industry, the diversity of fungi with heat resistance abilities is poorly studied. Sampling of boreal forest soils in Canada in combination with a heat-shock treatment (75 °C, 30 min) yielded, among others, four heat resistant, mesophilic fungal isolates. Based on rDNA barcode sequences, the novel isolates were assigned to Basidiomycota. In this study, we use macromorphological and micromorphological observations, cultivation assays and comparative genomics for physiological characterization, interspecific differentiation, and phylogenetic placement of these isolates. A phylogeny of 38 single-copy orthologous genes, an orthology analysis, and septal pore type analysis revealed the isolates as representatives of two new basidiomycetous species of the novel class Peribolosporomycetes, a sister lineage to all other members of Ustilaginomycotina. Further genomic and phenotypic data support two different species (Peribolospora kevripleyi, Peribolospora baueri), which are heat resistant and osmotolerant.

Correction to: Communications Biology https://doi.org/10.1038/s42003-022-04141-x, published online 16 November 2022.In the original version of the Article, an incorrect additional description of panel b in Figure 1 was included. The following sentence has now been removed:b Lignocellulose is a complex and recalcitrant polymer built up from cellulose, xylan (hemicellulose), and lignin. Its degradation requires the synergistic action of various different enzymes.

Activity-based protein profiling is used to screen lignocellulose-degrading enzymes from the white rot fungus Phanerochaete chrysosporium to identify those specifically active in the presence of wood substrate.Activity-based protein profiling (ABPP) has emerged as a versatile biochemical method for studying enzyme activity under various physiological conditions, with applications so far mainly in biomedicine. Here, we show the potential of ABPP in the discovery of biocatalysts from the thermophilic and lignocellulose-degrading white rot fungus Phanerochaete chrysosporium. By employing a comparative ABPP-based functional screen, including a direct profiling of wood substrate-bound enzymes, we identify those lignocellulose-degrading carbohydrate esterase (CE1 and CE15) and glycoside hydrolase (GH3, GH5, GH16, GH17, GH18, GH25, GH30, GH74 and GH79) enzymes specifically active in presence of the substrate. As expression of fungal enzymes remains challenging, our ABPP-mediated approach represents a preselection procedure for focusing experimental efforts on the most promising biocatalysts. Furthermore, this approach may also allow the functional annotation of domains-of-unknown functions (DUFs). The ABPP-based biocatalyst screening described here may thus allow the identification of active enzymes in a process of interest and the elucidation of novel biocatalysts that share no sequence similarity to known counterparts.

Patterns and drivers of succession provide insight into the mechanisms that govern community assembly and are indicators of community resilience and stability but are still poorly understood in microbial communities. We assessed whether the successional trends of woody vegetation are mirrored by foliar fungal endophyte communities of three tree species that are abundant across the woody successional gradient using a total amplicon sequencing approach. Additionally, we test the relative contribution of host identity, abiotic predictors, biotic factors, and spatial distance between sites in predicting community composition and species richness of endophyte communities. Unlike the woody community, endophyte communities showed no consistent evidence of deterministic successional trends. Host identity was the most important factor structuring fungal endophyte community composition. Spatial distance played some role in explaining differences in community composition, but the effects of this and other environmental variables were small and not consistent between different host species. Much of the variation in endophyte composition remained unexplained. Host identity was most important in predicting endophyte richness. Although endophyte communities showed no deterministic succession, community assembly was most strongly influenced by host identity and spatial distance.

Fungal communities in above-ground tree tissues are hyperdiverse and are influenced by biotic interactions with other organisms living in or on these tissues. These biotic interactions are, however, still poorly understood. In this study, we aimed to understand how insect-associated gall formation on Eucalyptus foliage correlates with the diversity of foliar fungal communities in surrounding healthy leaf tissue, as well as the co-occurrence patterns among the members of the fungal community. We used ITS metabarcoding to characterise the foliar fungal communities of 179 individual E. grandis trees. These trees were assigned to infestation levels of the wasp Leptocybe invasa (Eulophidae: Hymenoptera), which causes gall formation on shoot tips and leaves of its host. Fungal community networks were calculated using a Pearson correlation coefficient. The composition and diversity of fungal communities were influenced by the severity of L. invasa infestations. We identified potential Eucalyptus pathogens with high sequence abundance at all disease severity levels, but network analysis indicated that the co-occurrence of potential pathogens between no to mild and medium to heavy infestation differed significantly. A better understanding of microbial interactions, especially the role of pathogens, can be useful for controlling disease- and beneficial host-associated microbial communities.

Fungal communities in above-ground tree tissues are hyperdiverse and are influenced by biotic interactions with other organisms living in or on these tissues. These biotic interactions are, however, still poorly understood. In this study, we aimed to understand how insect-associated gall formation on

Yeasts are integral parts of phylloplane communities of temperate regions, where ecosystems are not only influenced by short-term fluctuations in abiotic conditions, but additionally by cyclic seasonal changes. Phylloplane yeasts possess physiological adaptations, such as pigmentation and extracellular polysaccharides that enable them to resist harsh conditions encountered in these environments. Additionally, through production of plant hormone-like metabolites, they also might influence the behavior, fitness, and growth of their plant host. Here we review how the understanding of yeasts in this environment has improved in the last years due to discoveries in new habitats, new developments in taxonomy, but also the application of environmental sequencing and genomics. These new technologies, as well as traditional approaches, have made it clear that yeasts are not only occupying this environment to gain nutrients, but they are active participants that shape the structure of microbial communities by diverse interactions with other community members.