Abstract
BACKGROUND: Composting converts organic residues into stable organic matter and nutrients under aerobic conditions, improving soil properties and microbiome balance, while mitigating environmental impacts. Although microbiomes of various compost types have been studied, information is still fragmented and often not tailored to specific raw material combinations. In particular, little is known about the fungal communities involved in composting dairy plant wastewater sludge mixed with garden trimmings. This data paper contributes to filling that gap by providing a comprehensive taxonomic inventory. NEW INFORMATION: We provide a fungus-focused dataset from 18 compost samples generated from a 1:1 (w/w) mix of garden trimmings and dairy plant wastewater sludge, collected at three process stages (thermophilic start/end; mid-cooling and maturation) under two turning regimes. Shotgun metagenomes were taxonomically annotated against NCBI taxonomy (accessed 19 Feb 2025). Only Fungi were detected within Eukarya, spanning nine phyla; Ascomycota (60.8%), Mucoromycota (17.76%), Basidiomycota (8.50%) and Chytridiomycota (7.21%) comprised 94.27% of the taxonomic features. We report 417 genera (13 >1% relative abundance each); top: Aspergillus (17.93%), Rhizopus (8.61%), Chaetomium (4.83%), Aureobasidium (3.09%), Madurella (2.85%), Paramicrosporidium (2.71%), Rhizophagus (1.88%), Rasamsonia (1.81%), Hyaloraphidium (1.39%), Thermochaetoides (1.31%), Talaromyces (1.19%), Trichoderma (1.15%), Podospora (1.06%) comprised 49.81% of the taxonomic feature abundance. Overall 663 taxa were identified (578 species, 416 genera, 230 families, 106 orders, 48 classes and 9 phyla). The dataset (DwCA; 663 occurrences) is intended to serve as a reference for compost mycobiomes and will be available via GBIF (DOI 10.15468/nmpzwr).