Study On The Symbiotic Microbial Communities And Ingredient Contents Of Natural Cordyceps Militaris In Yunnan Province

Cordyceps militaris(Link.Fries)Link,an important fungal resource,is rich in various bioactive components and pharmacological effects.However,the strain of C.militaris degenerates,causing a significant decline in the content of active ingredients and impacting its healthy development.Wild C.militaris is widely distributed and as an important germplasm resource for new variety breeding.The quality of C.militaris varies according to habitat,which may be due to differences in microbial community compositions.Therefore,this study contains:The compositions of endophytic and habitat soils bacteria and fungi(symbiotic microorganisms)in four C.milltaris populations from Chuxiong,Qujing,and Kunming in Yunnan Province and Tieling in Liaoning Province,were studied using high-throughput sequencing.The results showed that the richness and diversity of the natural C.militaris symbiotic microbial communities in different populations were significant,with the Yunnan population having a higher richness and diversity than the Liaoning population.The compositions of the endophytic microbial communities in four C.militaris populations were similar,but the composition of the soil microbial community in the Liaoning population of C.militaris habitat differs significantly from that in Yunnan.Using culture-dependent methods,bacteria and fungi were isolated,identified,and analyzed for diversity in the Liaoning the four C.militaris populations,and the antimicrobial activity was tested using the plate confrontation method.The results were as follows: For bacteria,a total of 233 strains belonging to 4 phyla,27 genera,and 65 species of endophytic bacteria in C.militaris were obtained,along with 307 strains belonging to 4 phyla,32 genera,and 85 species of habitat soil bacteria.The dominant bacterial genera common to all four populations were Bacillus,Enterobacter,and Acinetobacter.For fungi,a total of 86 strains belonging to 4 phyla,22 genera,and51 species of endophytic fungi were obtained,along with 71 strains belonging to 4phyla,22 genera,and 46 species of habitat soil fungi.The dominant fungal genera common to all four populations l were Aspergillus,Fusarium,and Trichoderma.The dominant species varied among the populations.The antibacterial activity test results of 190 bacteria and 150 fungi showed that 145 bacterial strains and 42 fungal strains had antibacterial activity against more than one common pathogenic bacterium,with initial screening positive rates of 76.32% and 28.00%,respectively.Furthermore,58 bacterial strains and 34 fungal strains showed varying degrees of antagonistic ability against more than one plant pathogenic fungus,with initial screening positive rates of30.53% and 22.60%,respectively.Which contains a variety of strains with exceptional antibacterial activity.The biomass and active ingredient content of C.militaris mycelia from the four populations were analyzed.C.militaris was cultured in stationary conditions,and mycelia were collected at different time points.The contents of five active components were detected using colorimetry and a high-performance liquid chromatography.The results showed that the contents of polysaccharides,cordycepic acid,and adenosine in the four populations were higher during 30-50 days of culturing and then decreased with extended culture time,while the contents of saponins and cordycepin reached their peak values after 50 days of culturing.Moreover,radar chart comprehensive evaluation showed that the quality of C.militaris from the Chuxiong population was excellent,with strains FZC7 and FZC8 being high-quality strains with uniform substance distribution.In this study,the biomass and multiple active ingredient contents of the mycelia of C.militaris from the four populations were measured and analyzed.The results demonstrated that the quality of C.militaris from the Chuxiong population was excellent,and the high-quality strains FZC7 and FZC8 screened from it were beneficial to the exploration and utilization of C.militaris germplasm resources,which was important for industrial development and the development of local characteristic germplasm resources.High-throughput sequencing and culturedependent methods confirmed that the symbiotic microorganisms of C.militaris were rich and diverse in different populations,with stability and differences.Correlation analysis revealed that many symbiotic microorganisms were related to the content of main components of C.militaris.The strains with broad-spectrum and efficient antibacterial activity that were screened also provide strain resources for the subsequent exploration of antibacterial active substances.