Diversity Of Endophytic Fungi Of Ginseng And Fermentation Of Ginsenosides

As a traditional precious supplement,ginseng is highly regarded by people for its high medicinal value.Ginsenoside is the main medicinal ingredient of ginseng to exert various pharmacological and biological activities.Endophytes are microorganisms that live in the intercellular space of plant tissues for a period of time or all of their symbiosis,and their presence does not cause significant pathological changes in the host.Endophytes in ginseng can not only transform ginsenosides,but also produce ginsenosides by self-fermentation.The endophytic bacteria in ginseng were isolated and purified,and then the endophytic bacteria capable of producing ginsenosides were screened and their biological characteristics were studied to optimize the fermentation process.Thus it provides new methods and ways for the acquisition of ginsenosides and large-scale industrial production.Several ginseng endophytes were isolated and purified by microbial culture method,and their identification and diversity analysis were carried out.Then,by culturing the endophytic bacteria of ginseng,the content and type of ginsenoside in the fermented extract were measured,and the endophytic bacteria capable of producing ginsenoside by self-fermentation were selected.Finally,the fermentation conditions of endophytic bacteria of ginseng were preliminarily optimized to explore the optimal fermentation conditions for endophytic bacteria.Twenty-six strains of endophytic bacteria were obtained by separation and purification.Morphological observation and molecular identification of these endophytes showed that there were sixteen endophytic fungi,ten endophytic bacteria,and endophytes with different appearances.There are seven types of fungi and three types of bacteria.Twelve endophytic fungi were identified by molecular identification.Twelve endophytic fungi were found to belong to 8 genera and 9 species,which showed that the isolated endophytic bacteria had rich diversity.The saponin content of the twenty-six strains of ginseng endophytic liquid fermentation extracts indicated that the four endophytes of NSJ0,NSJ1,NSJ16 and NSJ105 were able to produce saponins,of which NSJ0 had the shortest culture period and the highest saponin yield.And the type of monomeric saponin produced by NSJ0 is also the most relative to the other three endophytes.Therefore,the NSJ0 strain is a good endophytic strain that can be used for further investigation.LC-MS identification of four strains of saponin endophytic fermentation extracts showed that endophytic bacteria produced as many as several kinds of compounds,and some strains produced more than one saponin,which also reflected endophytic metabolites diversity.The mixed fermentation design method was used to uniformly design the fermentation condition of endophytic bacteria,and 12 groups of fermentation schemes were obtained.Four endophytic bacteria producing saponins were selected for liquid fermentation according to the above scheme,and the total saponin content and total saponin yield in each bottle of fermentation extract were determined.Therefore,the best fermentation scheme for each strain was obtained.According to the results of saponin determination in the fermentation extract,the N8 regimen of NSJ0 strain can obtain the highest total saponin content,the N4 regimen can obtain the highest total saponin yield;the N11 regimen of NSJ1 strain can obtain the highest total saponin content and total saponin yield;the N7 scheme of NSJ16 strain can get the highest total saponin content and total saponin production;N9 regimen of NSJ105 strain can obtain the highest total saponin content and total saponin yield.