Study On Microbial Diversity And Their Antibacterial Activity Isolated From Soil Sample Collected In Meili Snow Mountain

Meili Snow Mountain National Park is the core area of the World Natural Heritage "Three Parallel Rivers" nature reserve,which is rich in microbial resources,at present,there is still no research on microbial diversity in the Yubeng area of Meili Snow Mountain at home and abroad.In this study,sixty-two soil samples collected from Yubeng area were selected for microbial diversity study,and Mi Seq high-throughput sequencing was performed for the fungal and bacterial community structure analysis by ASV cluster analysis.The results showed that the species diversity of fungi and bacteria decreased with the increase of altitude,and the overall difference in species diversity in winter and summer is not significant;soil fungal and bacterial community composition varied greatly in winter and summer.Compared with the winter sample,the soil fungal and bacterial communities varied greatly in three different altitudes in summer.In terms of species composition,Agaricomycetes was the dominant group,followed by Leotiomycetes,Dothideomycetes,Tremellomycetes and Archaeorhizomycetes,their relative abundance varies significantly by season,among them,the relative abundances of Leotiomycetes and Dothideomycetes changed significantly with different altitudes.Alphaproteobacteria was the dominant group,followed by Actinobacteria and Gammaproteobacteria,among them,the relative abundances of Gammaproteobacteria,Acidobacteria,Thermoleophilia,Bacteroidia,Blastocatellia and Chloroflexia varied greatly in different altitudes.A total of 552 of actinomycetes strains belonging to 9 orders,15 families,30 genera,and 176 species(21 of which were potential new species)were isolated by using glycerol-asparagine agar,humic agar and citrate agar as culture medium;1335 fungi strains belonging to 4 phyla,11 classes,37 orders,93 families,208 genera,and 422 species(93 of which were potential new species)were isolated by using modified martin agar,potato glucose agar and sabaurauds agar as culture medium.By morphological and phylogenetic analysis,a new species of Tetracladium meiliense sp.nov.(Ascomycota-Leotiomycetes-Helotiales-Tetracladium)was described and identified.Eleven indicator fungi and bacteria including Phoma herbarum,Fusarium solani,Plectosphaerella cucumerina,Alternaria panax,Fusarium oxysporum,Epicoccum nigrum,Candida albicans,Pseudomonas aeruginosa,Bacillus subtilis,Staphylococcus aureus,Ampicillin-resistant,Kanamycin-resistant,and Streptomycin-resistant Alcaligenes faecalis subsp.phenolicus were used as targets for the test of the antibacterial activity of 779 fungi and 179 actinobacteria,the results showed that forty-two fungi(5.4 %)showed broad-spectrum antagonistic activity against eleven indicator fungi and bacteria,thirteen actinomycetes strains showed antagonistic activity against four indicator bacteria,and fifteen actinomycetes exhibited antagonistic activity against seven indicator fungi.