Diversity and Isolation of Endophytic Fungi in Panax japonicus and Biotransformation Activity on Saponins

Abstract

aims: To explore the diversity and isolation of endophytic fungi in Panax japonicus and biotransformation activity on saponins background: Deglycosylated ginsenosides present in very small amounts are usually more pharmacologically active than glycosylated ginsenosides due to their higher bioavailability. It is possible to gain a thorough understanding of the endophytic fungal community composition and biodiversity of P. japonicus at various growth stages by analyzing the community structure as a starting point for researching host-endophyte interactions. For the first time, our study discloses the abundance and diversity of endogenetic fungi resources of differently aged P. japonicus by high-throughput sequencing. Meanwhile, the isolation and identification of endophytic fungi from P. japonicus were performed. Furthermore, the total saponins of P. japonicus (TSPJ) were used as substrates to screen the transformation functions of the isolated endophytic fungi and produce target deglycosylated saponins. To the best of our knowledge, this is the first report on the saponins biotransformation activities of cultivable endophytic fungi associated with P. japonicus. objective: This study reports the diversity and community structure differences of the endophytic fungi of Panax japonicus of different ages to obtain novel endophytic fungi with glycoside hydrolytic activity for rare saponins production. method: This study used the high-throughput sequencing method to analyze the diversity and community structure of endophytic fungi of P. japonicus. The endophytic fungi were processed by traditional isolation, culture, conservation and ITS rDNA sequence analyses. Then using the total saponins of P. japonicus as the substrate to evaluate the glycoside hydrolytic activity. result: The composition analysis of the community structure showed that the abundance, evenness and diversity of endophytic fungi of nine-year-old P. japonicus were the best among all samples. A total of 210 endophytic fungi were isolated from P. japonicus samples and further annotated by sequencing the internal transcribed spacer. Then the biotransformation activity of obtained strains was further examined on total saponins of P. japonicus (TSPJ), with a strain identified as Fusarium equiseti (No.30) from 7-year-old P. japonicus showing significant glycoside hydrolytic activity on TSPJ, including Ro→ZR1，RT1→RP1，IV→VI and IVa→CE. conclusion: These results reveal the diversity and community structure differences of the endophytic fungi of P. japonicus with different ages and establish a resource library of endophytic fungi of P. japonicus. More importantly, we identified a valuable endophytic fungus with glycoside hydrolytic activity and provided a promising convenient microbial transformation approach to produce rare ginsenosides. other: Nothing