Institute of Microbiology, Microbial Communication, Friedrich Schiller University Jena, Neugasse 25, D-07743 Jena, Germany.
Institute for Geosciences, Applied Geology, Friedrich Schiller University Jena, Burgweg 11, D-07749 Jena, Germany.
FEMS Microbiol Lett. 2019 Jul 1;366(13). doi: 10.1093/femsle/fnz167.
Belowground ecosystems are accessible by mining, where a specific microbial community can be discovered. The biodiversity of a former alum mine rich in carbon, but with a low pH of 2.6-3.7, was evaluated by DNA- and cultivation-dependent methods using samples of the black slate rock material, secondary mineralization phases and seepage water. Pyrite oxidation within the low-grade metamorphic Silurian black slate established high concentrations of Fe and $\rm{SO}_4^{2-}$ forming the extreme conditions visible with acidophilic and Fe-oxidizing microorganisms. In addition, an unexpected predominance of fungi in this C-rich and acidic cave ecosystem, including high numbers of Mucoromycota and Mortierellomycota, was detected. Therefore, fungal cultures were obtained, mainly from the secondary mineral phases that are iron phosphates. Hence, the fungi might well have been involved in phosphate mobilization there. The rock material itself is rich in organic carbon that can be used by oxidase activity. The cultivation setup mimicked the cave conditions (low temperature, low pH, oxic conditions), with one oligotrophic and one medium rich in nutrients that allowed for isolation of different fungal (and eutrophic bacterial) groups. The acidic conditions prevented the occurrence of many basidiomycetes, while the isolated fungi could survive these adverse conditions.
地下生态系统可以通过采矿来探索，在那里可以发现特定的微生物群落。本研究采用 DNA 依赖和培养依赖的方法，对富含碳但 pH 值低（2.6-3.7）的前明矾矿的生物多样性进行了评估，使用了黑石板岩材料、次生矿化相和渗流水的样本。低品位变质的志留纪黑石板中的黄铁矿氧化作用导致了高浓度的 Fe 和 $\rm{SO}_4^{2-}$，形成了嗜酸和 Fe 氧化微生物可见的极端条件。此外，在这个富含 C 和酸性的洞穴生态系统中，还检测到真菌的数量出乎意料地多，包括高数量的毛霉门和被孢霉门。因此，从次生矿物相中获得了真菌培养物，主要是铁磷酸盐。因此，真菌可能参与了那里的磷酸盐的生物地球化学循环。岩石材料本身富含有机碳，可以被氧化酶活性利用。培养装置模拟了洞穴条件（低温、低 pH 值、需氧条件），其中一个是贫营养的，一个是富含营养的，这允许分离不同的真菌（和富营养细菌）群。酸性条件阻止了许多担子菌的出现，而分离出的真菌可以在这些不利条件下存活。
