Metagenomic Survey of Compost Fungi from Terceira (Azores Archipelago)

Compost samples were collected at the early and late thermophilic stages and at the mid-cooling and maturation stages, and their microbiomes were characterized using a shotgun metagenomic sequencing approach. Within Eukarya, only the kingdom Fungi was detected: nine phyla, 48 classes, 105 orders, 230 families, 417 genera, and 578 species (87.18% of all 663 taxa). <a name="_Hlk209112295">The genus Aspergillus showed the highest estimated relative taxon abundance (17.93%), and this dominance was reflected at higher taxonomic ranks as well: phylum Ascomycota (60.80%), class Eurotiomycetes (24.12%), order Eurotiales (22.77%), and family Aspergillaceae (19.07%).</a>The inferred metabolic or ecological roles of the identified taxa during composting included: (i) decomposers and nutrient cyclers; (ii) biocontrol and cellulolytic fungi; (iii) yeasts and opportunistic fungi; (iv) microsporidia and chytrids associated with aquatic or anaerobic niches; and (v) mycorrhizal fungi.