![]() ![]() Despite the majority of these unexplored lineages have reduced genome sizes and minimal biosynthetic capacity, they were proposed to represent a major uncharacterised portion of microbial diversity and inhabiting every possible metabolic niche. These uncultured microbial community members represent a vast untapped and uncharacterised resource of biological information, representing the ‘microbial dark matter’ (MDM) of many microbial ecosystems. In light of our findings, we propose H 2, ribose and CO/CO 2 as the main energy currencies of the MDM community in these mat systems.Ī vast ‘known-unknown’ and even ‘unknown-unknown’, many microorganisms have yet to be unlocked from a majority of Earth’s ecosystems. Diversity-generating retroelements were prominent in DPANN archaea that likely facilitate the adaptation to a dynamic, host-dependent lifestyle. Putative schizorhodopsins were also identified in Parcubacteria, Asgard archaea, DPANN archaea, and Bathyarchaeota, allowing these members to potentially capture light energy. ![]() High capacity of hydrogen production was found among Shark Bay MDM. Several forms of RuBisCo were identified, allowing putative CO 2 incorporation into nucleotide salvaging pathways, which may act as an alternative carbon and phosphorus source. Despite possessing reduced-size genomes, the MDM MAGs are capable of fermenting and degrading organic carbon, suggesting a role in recycling organic carbon. This study reports novel microorganisms (Zixibacterial order GN15) putatively taking part in dissimilatory sulfate reduction in surface hypersaline settings, as well as novel eukaryote signature proteins in the Asgard archaea. The latter includes the first putative Heimdallarchaeota MAG obtained from any microbial mat system. We classified bacterial MDM from the PVC group, FCB group, Microgenomates, Parcubacteria, and Peregrinibacteria, as well as a high proportion of archaeal MDM under the TACK, DPANN, Altiarchaeales, and Asgard archaea. We reconstructed 115 metagenome-assembled genomes (MAGs) affiliated to MDM, spanning 42 phyla within the bacterial and archaeal domains. ![]() These enigmatic groups - ‘microbial dark matter’ (MDM) - are hypothesised to play key roles in microbial mats. These ecosystems have been shown to possess a substantial abundance of uncultivable microorganisms. Shark Bay, Australia, harbours one of the most extensive and diverse systems of living microbial mats, that are proposed to be analogs of some of the earliest ecosystems on Earth. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |