Institute of Fungus Resources, College of Life Science, Guizhou University, Guiyang, Guizhou, China.
Anshun Branch of Guizhou Tobacco Company, Anshun, Guizhou, China.
Microbiol Spectr. 2024 Oct 3;12(10):e0105324. doi: 10.1128/spectrum.01053-24. Epub 2024 Aug 20.
infects insects and forms sclerotia within the insect remains, establishing insect-microbe complexes. Here, . sclerotia samples from a single location in China over a 5-year period were subjected to high-throughput DNA sequencing, and the core microbes (which were stably enriched in the sclerotia over the 5 years) were identified. Next, seven bacterial strains were isolated from the sclerotia, their biochemical characteristics were assessed, and they were co-cultured with to study their effects on metabolite production and biomass. Furthermore, the effects of NH, NO, and peptone media on were compared. The results showed that , , , , , , , , and were the core microbes. Although co-culture of with the seven bacterial strains isolated from the sclerotia did not directly increase the cordycepin level, they all had NO reduction ability, and four had urea decomposition ability. Meanwhile, in NH medium had an increased cordycepin level compared to in the other two media. From this, we inferred that bacteria in the sclerotia can convert NO to NH, and then cordycepin is produced using NH, which was confirmed by RNA-seq and real-time fluorescence quantitative PCR. Thus, bacteria in the sclerotia may indirectly affect the metabolite production by regulating nitrogen metabolism. In summary, there are stable core microbes in the sclerotia, and they may directly and indirectly affect the growth and metabolite production of .
The model species is rich in therapeutic compounds. It has recently been demonstrated that symbiotic microbes in sclerotia affect growth, development, and secondary metabolite production. In this study, core microbes were identified based on sclerotia samples obtained from the same site over 5 years. Additionally, bacterial strains isolated from sclerotia were found to affect metabolite production and nitrogen utilization, based on functional tests. Moreover, based on the bacterial nitrogen metabolism capacity in the sclerotia and its influence on metabolite production, we deduced that bacteria in the sclerotia can indirectly affect metabolite production by regulating nitrogen metabolism. This is the first report on how bacteria in the sclerotia affect metabolite production from the perspective of the nitrogen cycle. The results increase our understanding of microbial functions in sclerotia.
感染昆虫并在昆虫遗骸内形成菌核，从而建立昆虫-微生物复合体。在这里，对来自中国同一地点的 5 年时间内的 菌核样本进行了高通量 DNA 测序，并鉴定了核心微生物（在 5 年内稳定地在菌核中富集）。接下来，从 菌核中分离出了 7 株细菌，评估了它们的生化特性，并将它们与 共培养以研究它们对 代谢产物产生和生物量的影响。此外，还比较了 NH、NO 和蛋白胨培养基对 的影响。结果表明， 、 、 、 、 、 、 和 是核心微生物。虽然 与从菌核中分离出的 7 株细菌共培养并未直接增加虫草素水平，但它们都具有还原 NO 的能力，其中 4 株具有尿素分解能力。同时，与其他两种培养基相比，NH 中的 虫草素水平升高。由此推断，菌核中的细菌可以将 NO 转化为 NH，然后利用 NH 产生虫草素，这通过 RNA-seq 和实时荧光定量 PCR 得到了证实。因此，菌核中的细菌可能通过调节氮代谢间接影响 的代谢产物产生。总之，菌核中有稳定的核心微生物，它们可能直接或间接影响 的生长和代谢产物产生。
