Update(MM/DD/YYYY):08/27/2021
A membrane-bounded genome in a bacterium isolated from a deep biosphere
– Isolation of a novel bacterium of an as-yet uncultivated phylum reveals a unique cell structure –
Researchers: KATAYAMA Taiki, Senior Researcher, YOSHIOKA Hideyoshi, Group Leader. Geomicrobiology Research Group, Research Institute for Geo-Resources and Environment. NOBU Masaru Konishi, Researcher, KUSADA Hiroyuki, Researcher, MENG Xian-Ying, Technical Staff, KAMAGATA Yoichi, Visiting Researcher, TAMAKI Hideyuki, Group Leader. Microbial and Genetic Resources Research Group, Bioproduction Research Institute.
Key point
In collaboration with JEOL Ltd. and Marine Works Japan Ltd., the researchers in AIST succeeded in culturing strain RT761, a bacterium that plays an important role in methane production in deep subsurface environments such as natural gas fields.
Atribacter laminatus RT761, the novel bacterium in a new phylum Atribacterota
This figure shows the intracellular structure of RT761 during cell division based on microscopic observation; Genomic DNA (gray line) is compartmentalized by an intracellular membrane (dark yellow).
Background
Living organisms are classified into two groups: prokaryotes (e.g., bacteria such as lactic acid bacteria) and eukaryotes (e.g., humans, plants and animals). One of the critical differences between these two groups is the existence of a membrane surrounding genomic DNA inside the cell (i.e., nuclear membrane); no such a membrane had been discovered in prokaryotes.
New results
A. laminutus RT761, possessed an intracellular membrane surrounding the genomic DNA, possibly leading to the revisit of prokaryotic cell concepts. In addition, the new phylum, Atribacterota, representing this strain is known to be widely distributed in anoxic, deep subsurface environments where biogenic methane is deposited (such as natural gas fields, hydrate-bearing sediments, etc.). Therefore, the ecological characterization of Atribacterota members in future study directly links to understand biogenic methane production in deep biosphere.
Future research plans
In addition to the ecological characterization, the researchers are planning to study on physiological and cellular functions and evolution of this unique cell structure, i.e., intracellular membrane, in the Atribacterota phylum.