Investigation and research on fungal diversity of Platycladi Semen on Chinese market

Abstract

In the process of harvesting, production and processing, storage, and transportation, the traditional Chinese medicine Platycladi Semen is prone to mildew due to its own and environmental factors, which can nourish the production of toxic or pathogenic fungi, and even produce mycotoxins, which affects the safety of clinical medication. The 2020 edition of Chinese Pharmacopoeia limits the highest standard of aflatoxin content in Platycladi Semen. However, there are few studies on the fungal contamination of Platycladi Semen, and it is difficult to prevent and control it in a targeted manner. Therefore, based on the Illumina NovaSeq6000 platform, this article uses ITS sequence amplicon technology to analyze the distribution and diversity of fungi in 27 batches of commercially available Platycladi Semen in the Chinese market. A total of 10 phyla, 35 classes, 93 orders, 193 families, 336 genera, and 372 species of fungi were identified in China. Among them, Aspergillus, Alternaria spp. were dominant, 20 batches of samples were detected for A. flavus, 10 batches of samples were detected for A. nidulans, and all samples were detected for potential pathogenic fungi such as A. fumigatus and A. niger. According to diversity analysis, the diversity of the fungal communities in the samples from Gansu province was high, the samples in Shandong province contain the largest number of fungal species, and the samples in Guangxi province had the lo-west diversity and the least number of species. In most samples, pathogenic fungi such as A. fumigatus, A. niger, A. flavus, A. parasiticus were detected in varying degrees. This study systematically investigated the fungal contamination of Platycladi Semen from the markets in the last link of the its industrial chain, and clarified the distribution of Platycladi Semen fungi, especially toxin-producing fungi, and provided theoretical basis for the targeted prevention and control of fungal contamination in Platycladi Semen.