Department of Applied Biology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany.
Sci Rep. 2017 Jun 12;7(1):3289. doi: 10.1038/s41598-017-03315-6.
This study describes the laboratory cultivation of ARMAN (Archaeal Richmond Mine Acidophilic Nanoorganisms). After 2.5 years of successive transfers in an anoxic medium containing ferric sulfate as an electron acceptor, a consortium was attained that is comprised of two members of the order Thermoplasmatales, a member of a proposed ARMAN group, as well as a fungus. The 16S rRNA identity of one archaeon is only 91.6% compared to the most closely related isolate Thermogymnomonas acidicola. Hence, this organism is the first member of a new genus. The enrichment culture is dominated by this microorganism and the ARMAN. The third archaeon in the community seems to be present in minor quantities and has a 100% 16S rRNA identity to the recently isolated Cuniculiplasma divulgatum. The enriched ARMAN species is most probably incapable of sugar metabolism because the key genes for sugar catabolism and anabolism could not be identified in the metagenome. Metatranscriptomic analysis suggests that the TCA cycle funneled with amino acids is the main metabolic pathway used by the archaea of the community. Microscopic analysis revealed that growth of the ARMAN is supported by the formation of cell aggregates. These might enable feeding of the ARMAN by or on other community members.
本研究描述了 ARMAN（古菌里士满矿嗜酸纳米生物）的实验室培养。经过 2.5 年在含有硫酸铁作为电子受体的缺氧培养基中的连续传代，获得了一个由两个 Thermoplasmatales 目成员、一个拟议的 ARMAN 组成员以及一个真菌组成的联合体。一个古菌的 16S rRNA 同一性与最密切相关的分离物 Thermogymnomonas acidicola 相比仅为 91.6%。因此，该生物是一个新属的第一个成员。富集培养物主要由这种微生物和 ARMAN 组成。群落中的第三个古菌似乎数量较少，其 100% 的 16S rRNA 同一性与最近分离的 Cuniculiplasma divulgatum 相同。富集的 ARMAN 物种可能无法进行糖代谢，因为在宏基因组中无法识别糖分解代谢和合成代谢的关键基因。代谢转录组学分析表明，TCA 循环与氨基酸一起成为群落中古菌的主要代谢途径。显微镜分析表明，ARMAN 的生长得到细胞聚集体的形成的支持。这些可能使 ARMAN 通过或在其他群落成员上进行喂养。
