Microplastic (MP) is a pervasive pollutant in nature that is colonised by diverse groups of microbes, including potentially pathogenic species. Fungi have been largely neglected in this context, despite their affinity for plastics and their impact as pathogens. To unravel the role of MP as a carrier of fungal pathogens in terrestrial ecosystems and the immediate human environment, epiplastic mycobiomes from municipal plastic waste from Kenya were deciphered using ITS metabarcoding as well as a comprehensive meta-analysis, and visualised via scanning electron as well as confocal laser scanning microscopy. Metagenomic and microscopic findings provided complementary evidence that the terrestrial plastisphere is a suitable ecological niche for a variety of fungal organisms, including important animal and plant pathogens, which formed the plastisphere core mycobiome. We show that MPs serve as selective artificial microhabitats that not only attract distinct fungal communities, but also accumulate certain opportunistic human pathogens, such as cryptococcal and Phoma-like species. Therefore, MP must be regarded a persistent reservoir and potential vector for fungal pathogens in soil environments. Given the increasing amount of plastic waste in terrestrial ecosystems worldwide, this interrelation may have severe consequences for the trans-kingdom and multi-organismal epidemiology of fungal infections on a global scale.

The Dead Sea is one of the most hypersaline habitats on Earth. The fungus Eurotium rubrum (Eurotiomycetes) is among the few species able to survive there. Here we highlight its adaptive strategies, based on genome analysis and transcriptome profiling. The 26.2 Mb genome of E. rubrum shows, for example, gains in gene families related to stress response and losses with regard to transport processes. Transcriptome analyses under different salt growth conditions revealed, among other things differentially expressed genes encoding ion and metabolite transporters. Our findings suggest that long-term adaptation to salinity requires cellular and metabolic responses that differ from short-term osmotic stress signalling. The transcriptional response indicates that halophilic E. rubrum actively counteracts the salinity stress. Many of its genes encode for proteins with a significantly higher proportion of acidic amino acid residues. This trait is characteristic of the halophilic prokaryotes as well, supporting the theory of convergent evolution under extreme hypersaline stress.

Based on a study of 22 sites in northeastern Brazil, including the three main vegetation types, coastal Mata Atlântica (Zona da Mata), Caatinga and Brejos de Altitude (rain forest enclaves in Caatinga areas), we studied the distribution and habitat preferences of 456 crustose and microfoliose lichen species. Alpha-diversity ranged between three and 99 species per site, with Zona da Mata and Brejos de Altitude showing higher numbers than Caatinga sites. Beta-diversity (dissimilarity) was highest between Zona da Mata sites and, as a whole, the Zona da Mata showed the highest gamma-diversity, with a total of 334 species. Site ordination by non-metric multidimensional scaling (NMS), as well as cluster analysis, both using Sørensen's coefficient of dissimilarity, show that Zona da Mata and Caatinga sites have distinctive lichen species compositions, with the isolated Brejos de Altitude being more similar to coastal Zona da Mata than to Caatinga sites. Exposed Zona da Mata sites have certain species in...