Fungal microbiome related to mycotoxin contamination in medicinal and edible seed Semen Persicae

Medicinal and edible seed Semen Persicae is susceptible to mycotoxin and fungal contamination. However, the occurrence of mycotoxin contamination and fungal infection is still unclear. In this paper, ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry and high-throughput sequencing were conducted to determine the mycotoxin contents and fungal abundances of Semen Persicae. 42.86% of samples were positive for aflatoxin B1 (26.48-48.37 μg/kg) and 28.57% of samples were positive for aflatoxin B2 (1.47-4.82 μg/kg). Ochratoxin A and fumonisin B1 were only detected in one sample (91.02 and 34.61 μg/kg, respectively). Chao 1 and Shannon indices were significantly higher in the Dalian of Liaoning, Baotou of Innermongolia and Langfang of Hebei regions than in other groups. Ascomycota, Basidiomycota, Wallemia, Candica, Saccharomyces and Aspergillus were the predominant fungi and they were significantly region-specific. Simultaneously, the diversity, composition and co-occurrence network complexity in the mycotoxin-free group were significantly higher than those in the mycotoxin-contaminated group. Spearman correlation analysis showed aflatoxins, ochratoxin A and fumonisins contents were positively and significantly correlated with the abundances of Aspergillus, Rhodotorula, Wallemia and Candida. In conclusion, this study reported the prevalence of mycotoxin contamination and the great diversity of fungi associated with Semen Persicae for the first time, providing an early warning for subsequent potential mycotoxin biosynthesis.