Endogenous bacteria inhabiting the Ophiocordyceps highlandensis during fruiting body development

Abstract

Background The genus Ophiocordyceps, which includes Ophiocordyceps sinensis, has been demonstrated to be one of the most valuable medicinal taxa. The low rate of larval infection and slow development that characterize the cultivation of this genus should be urgently addressed. To identify potential bioinoculants that stimulate the growth of Ophiocordyceps, O. highlandensis was selected as a model system, and a total of 72 samples were collected to systematically compare the microbial communities present during fruiting body development. By applying high-throughput 16S and ITS2 amplicon sequencing technology, the bacterial and fungal communities were identified in O. highlandensis and its surrounding soil, and the functional dynamics of the bacteria were explored. Results The results indicate that the most abundant bacteria across all the samples from O. highlandensis were Proteobacteria, Firmicutes and Bacteroidetes, while members of Ascomycota were detected among the fungi. The pathways enriched in the developmental stages were associated with carbohydrate degradation, nucleotides and pyridoxal biosynthesis, and the TCA cycle. Compared with that in the fungal community, an unexpectedly high taxonomic and functional fluctuation was discovered in the bacterial community during the maturation of O. highlandensis. Furthermore, bipartite network analysis identified four potential supercore OTUs associated with O. highlandensis growth. Conclusions All the findings of this study suggest unexpectedly high taxonomic and functional fluctuations in the bacterial community of O. highlandensis during its maturation. O. highlandensis may recruit different endogenous bacteria across its life cycle to enhance growth and support rapid infection. These results may facilitate Ophiocordyceps cultivation and improve the development of strategies for the identification of potential bioinoculant resources.

Microbial community composition and soil metabolism in the coexisting Cordyceps militaris and Ophiocordyceps highlandensis

“…In addition, the results of microbial source tracking confirmed that the fungal community of C. militaris was sourced from its soil microhabitat (Figure 6c), which was not the same as the fungal community of O. highlandensis (Figure 6d). Compared with that by C. militaris , we speculate that microbiome selection by naturally occurring O. highlandensis was weaker in the soil surrounding the fungus, which is consistent with findings from previous research [34]. This also indicates that other microbial factors might influence the formation of O. highlandensis .…”

Possible impacts of the predominant Bacillus bacteria on the Ophiocordyceps unilateralis s. l. in its infected ant cadavers

“…The biological properties associated with an outbreak of B. cereus/thuringiensis suggest potential benefits to O. unilateralis s. l . The sympatric bacteria have recently been noted to play crucial roles in the growth of parasitoid fungi 65 – 67 . However, the proliferation of B. cereus/thuringiensis appears coincidental rather than the result of long-term coevolution.…”

Impact of Cultivation Substrate and Microbial Community on Improving Mushroom Productivity: A Review

“…Multiple bacteria and fungi play important roles in the population differentiation, environmental suitability, infection mechanism, and quality of Ophiocordyceps sinensis [16,[137][138][139]. Proteobacteria, Firmicutes, Verrucomicrobia, and Deltaproteobacteria are the most relatively abundant bacteria detected during the life cycle of O. highlandensis [17]. Zhang et al [16] observed microbial communities in the soil that have been associated with naturally occurring C. militaris.…”

“…Some of these studies have involved Pleurotus spp. [14,15], Cordyceps militaris [16], and Ophiocordyceps highlandensis [17]. Nevertheless, little information on the microbial dynamics during substrate preparation or the cultivation of other mushrooms is known.…”