Uncovering fungal community composition in natural habitat of Ophiocordyceps sinensis using high-throughput sequencing and culture-dependent approaches

Abstract

Background: The fungal communities inhabiting natural Ophiocordyceps sinensis play critical ecological roles in alpine meadow ecosystem, contribute to infect host insect, influence the occurrence of O. sinensis , and are repertoire of potential novel metabolites discovery. However, a comprehensive understanding of fungal communities of O. sinensis remain elusive. Therefore, the present study aimed to unravel fungal communities of natural O. sinensis using combination of high-throughput sequencing and culture-dependent approaches. Results: A total of 280,519 high-quality sequences, belonging to 5 fungal phyla, 15 classes, 41 orders, 79 families, 112 genera, and 352 putative operational taxonomic units (OTUs) were obtained from natural O. sinensis using high-throughput sequencing. Among of which, 43 genera were identified in external mycelial cortices, Ophiocordyceps , Sebacinia , Archaeorhizomyces were predominant genera with the abundance of 95.86%, 1.14%, 0.85%, respectively. A total of 66 genera were identified from soil microhabitat, Inocybe , Archaeorhizomyces , unclassified Thelephoraceae , Tomentella , Thelephora , Sebacina , unclassified Ascomycota , unclassified Fungi were predominant genera with an average abundance of 53.32%, 8.69%, 8.12%, 8.12%, 7.21%, 4.6%, 3.08% and 3.05%, respectively. The fungal communities in external mycelial cortices were significantly distinct from the soil microhabitat. Meanwhile, seven types of culture media were used to isolate culturable fungi at 16°C, resulted in 77 fungal strains isolated by rDNA ITS sequence analysis, belonging to 33 genera, including Ophiocordyceps , Trichoderma , Cytospora , Truncatella , Dactylonectria , Isaria , Cephalosporium , Fusarium , Cosmospora and Paecilomyces , etc .. Among all culturable fungi, Mortierella and Trichoderma were predominant genera. Conclusions: The significantly differences and overlap in fungal community structure between two approaches highlight that the integration of high-throughput sequencing and culture-dependent approaches would generate more information. Our result reveal a comprehensive understanding of fungal community structure of natural O. sinensis , provide new insight into O. sinensis associated fungi, and support that microbiota of natural O. sinensis is an untapped source for novel bioactive metabolites discovery.