DNA metabarcoding of fungal communities in Heshouwu (Polygonum multiflorum Thunb.)

Heshouwu, derived from the dried root tuber of Polygonum multiflorum Thunb., is a widely used functional food and medicinal herb. Mycotoxin pollution of Heshouwu samples has become an emergent issue that cannot be ignored. In this study, the presence of fungi in commercial Heshouwu samples was investigated, and the differences in fungal community in samples from different collection sites and processing approaches were analyzed by DNA metabarcoding. Results showed that Ascomycota and Basidiomycota were the predominant phyla. At the genus level, Aspergillus (2.14%–94.05%), Cladosporium (0.22%–41.18%), Candida (0%–87.40%), Penicillium (0.01%–27.45%), and Alternaria (0%–32.29%) were the main genera. Meanwhile, six potential toxigenic fungi and one human pathogen, namely, Aspergillus flavus, Aspergillus nomius, Aspergillus tamarii, Fusarium solani, Penicillium paxillin, Penicillium steckii, and Candida tropicalis, were detected. In addition, differences in fungal diversity, community composition, trophic modes, and functional groups of Heshouwu samples from five collection sites and two processing approaches were observed. This study provides a comprehensive understanding of the fungal communities of Heshouwu, thereby providing a basis for future research on the prevention of mycotoxin contamination in this important medicinal herb.