Diversity of fungi on surface of Pheretima

Abstract

Traditional Chinese medicines( TCMs) are easily contaminated by fungi during planting,harvesting,processing,transportation and storage. The 2015 version of Chinese Pharmacopoeia stipulates the detection of aflatoxin in Dilong. After reviewing the literature,it has been found that there are no domestic and foreign scholars who have studied the surface fungi of Dilong. Pheretima,known as Dilong in China,is a commonly used TCMs in animal. In this experiment,8 batches of Dilong were collected from retail pharmacies in Beijing. The fungi on the surface of Dilong were cultured by traditional plate method and the single strain was obtained by the top purification method. The fungal colony morphology,microstructure characteristics and DNA barcode were used to isolate and identify the fungi. At the same time,based on Illumina Hi Seq 2500 high-throughput sequencing platform,the diversity of fungi on the surface of Dilong was analyzed. The results showed that 287 strains of 9 species of fungi were isolated and identified by plate method. Combined with 3 kinds of identification method,eight of nine fungi could be identified,respectively,Aspergillus niger,Penicillium,Alternaria nees,A. flavus,and Penicillium oxalicum,Humicola sp.,Talaromyces purpurogenus and A. insuetus,1 kind of fungi was not identified yet. Among them,Penicillium and Aspergillus were the dominant genus. The results of high-throughput sequencing belonged to 2 boundaries,6 gates,19 classes,44 orders,98 families,127 genus and 121 species in different classification levels. Wallemia,Aspergillus and Cordyceps were the dominant genus,and the relative abundances are 63. 33%,15. 28%,and 10. 28%,respectively. Through the diversity study on the surface fungi of Dilong in Beijing retail pharmacies,it can provide a reference for its safe storage and clinical use.