Cordyceps cicadae is an entomogenous fungus with important uses in traditional Chinese medicine. However, its wild resources have not met consumers’ demand due to excessive harvesting practices. Artificial cultivation is therefore an important alternative, but research on cultivating C. cicadae in natural habitats has not been reported. In this study, we aimed to explore the viability of cultivating C. cicadae in a natural habitat, in the soil of Pinus massoniana forest. We assessed and compared the yield, metabolite contents and bacterial community composition of C. cicadae grown in the Antheraea pernyi pupae at different growth stages, and under different cultivation conditions, in the soil of a natural habitat and in sterile glass bottles. Our results showed that cultivating C. cicadae in a natural habitat is feasible, with up to 95% of pupae producing C. cicadae fruiting bodies. The content of nitrogen compounds (amino acids) in C. cicadae cultivated in a natural habitat was significantly higher than in glass bottles, while the yield and carbon compound (mannitol and polysaccharide) and nucleoside (cordycepin and adenosine) contents were lower. Different bacterial genera were enriched in C. cicadae at different growth stages and cultivation environments, and these bacterial genera were closely related to metabolites contents during growth. This study demonstrated the viability of a novel cultivation method of C. cicadae, which could be used as an alternative to wild stocks of this fungus. These findings provided new insights into the growth mechanism of C. cicadae and its interaction with soil microorganisms.

In recent years, the herpes virus infectious hypothesis for Alzheimer’s disease (AD) has gained support from an increasing number of researchers. Herpes simplex virus (HSV) is a potential risk factor associated with AD. This study assessed whether HSV has a causal relationship with AD using a two-sample Mendelian randomization analysis model. Six single-nucleotide polymorphisms (SNPs) associated with HSV-1 and thirteen SNPs associated with HSV-2 were used as instrumental variables in the MR analysis. We estimated MR values of relevance between exposure and the risk of AD using inverse-variance weighted (IVW) method, MR-Egger regression (Egger), and weighted median estimator (WME). To make the conclusion more robust and reliable, sensitivity analyses and RadialMR were performed to evaluate the pleiotropy and heterogeneity. We found that anti-HSV-1 IgG measurements were not associated with risk of AD (OR, 0.96; 95% CI, 0.79–1.18; p = 0.736), and the same was true for HSV-2 (OR, 1.03; 95% CI, 0.94–1.12; p = 0.533). The findings indicated that any HSV infection does not appear to be a genetically valid target of intervention in AD.

Background Cordyceps militaris is a fungus that parasitizes insects. Compounds from C. militaris are valuable in medicine and functional food. There are many kinds of bacteria in the natural sclerotia of C. militaris. However, the community structure of microorganisms in samples from different places may be different, and their corresponding ecological functions require experimental verification. Methods We used high-throughput sequencing technology to analyze bacterial 16S rRNA gene sequences in sclerotia of three samples of C. militaris from Liaoning Province, China. We isolated, identified and verified the function of culturable bacterial strains from the sclerotia. Results Pseudomonas, Pedobacter, Sphingobacterium, and Serratia were the dominant bacterial genera in the sclerotia. And function prediction showed that Pseudomonas and Pedobacter could be heterotrophic, Sphingobacterium could decompose urea, and Serratia could reduce nitrate. Two strains of bacteria isolated from the sclerotia of C. militaris, N-2 and N-26, were identified as Stenotrophomonas maltophilia and Pseudomonas baetica, respectively, based on culture and biochemical characteristics. When these isolated strains were co-cultured with C. militaris, the mycelium biomass and mycelium pellet diameter decreased, and the content of extracellular polysaccharide increased. Strain N-26 decreased the cordycepin content in C. militaris. Conclusions Bacteria in sclerotia have an important effect on the growth of C. militaris and the production of its metabolites.

Background Cordyceps militaris is a fungus that parasitizes insects. Compounds from C. militaris are valuable in medicine and functional food. There are many kinds of bacteria in the natural sclerotia of C. militaris. However, the community structure of microorganisms in samples from different places may be different, and the corresponding ecological functions require experimental verification. Results We used high-throughput sequencing technology to analyze bacterial 16S rRNA gene sequences in sclerotia of three samples of C. militaris from Liaoning Province, China. Pseudomonas, Pedobacter, Sphingobacterium, and Serratia were the dominant bacterial genera in the sclerotia. Pseudomonas and Pedobacter are heterotrophic, Sphingobacterium decomposes urea, and Serratia reduce nitrate. Two strains of bacteria, N-2 and N-26, were isolated from the sclerotia of the C. militaris, cultured, biochemically characterized, and identified as Stenotrophomonas maltophilia and Pseudomonas baetica, respectively. When these isolated strains were respectively cocultured with C. militaris, the mycelium biomass, mycelium pellet diameter, and cordycepin content decreased. Conclusions Bacteria in sclerotia have an important effect on the growth of C. militaris and the production of its metabolites.