Moorella group

RANK: No rank

TAXONOMY: Bacteria -> Terrabacteria group -> Firmicutes -> Clostridia -> Thermoanaerobacterales -> Thermoanaerobacteraceae -> Moorella group


In early exponential growth phase, cells stain Gram-positive. However, some species stain negative during the late exponential and stationary growth phases. Straight rods with a tendency to polymorphism under stress conditions such as high glucose or high acetate concentrations. Physiology is obligately anaerobic, thermophilic, and chemolithoautotrophic and/or heterotrophic; produces acetate as sole or main fermentation product from sugars, C1 carbon sources, and other substrates. Produces nearly 3 moles of acetate per mole of glucose consumed, which is sometimes called “homoacetogenic” fermentation. While growing on substrates other than hexoses, CO, or CO2/H2, Moorella species can produce various products. May use nitrate, nitrite or fumarate as electron acceptors. Forms various aromatic compounds via decarboxylation of arylic acids, which are used as CO2 donors under CO2-limited conditions. The cell wall contains ll-diaminopimelate (DAP).

DNA G+C content (mol%): 53–55.

Type species: Moorella thermoacetica

Substrates/ Growth Factors
  • D-Glucose
  • Nitrite
  • Nitrate
  • Fumarate

  • Metabolic Endproducts
  • Acetic acid