strictly anaerobic

Edge evidence

• anoxic condition enables strictly anaerobic RO:0002327

  Strict anaerobes require oxygen-excluding conditions for growth.

  • DOI:10.1038/s41579-021-00583-y hypoxic or anoxic conditions Review supports anoxic environments as the ecological context for anaerobe growth.
• molecular oxygen inhibits strictly anaerobic RO:0002212

  Oxygen exposure blocks strict anaerobic growth.

  • DOI:10.1038/s41579-021-00583-y oxygen blocks their growth Supports oxygen as an inhibitory exposure for obligate anaerobes.
• molecular oxygen causes formation of reactive oxygen species biolink:produces

  Oxygen exposure can generate reactive oxygen stress.

  • DOI:10.1038/s41579-021-00583-y molecular oxygen and ROS Review links oxygen exposure to ROS stress in anaerobes.
• reactive oxygen species damages oxygen-sensitive enzymes

  ROS can impair oxygen-sensitive anaerobic enzyme systems.

  • DOI:10.1038/s41579-021-00583-y poisoning by molecular oxygen and ROS Supports enzyme vulnerability as a mechanism of oxygen toxicity.
• molecular oxygen oxidizes/inactivates iron-sulfur cluster enzymes

  Oxygen directly oxidizes mononuclear iron enzymes and solvent-exposed iron-sulfur clusters.

  • DOI:10.1128/iai.00502-24 "oxygen directly oxidizes mononuclear iron enzymes and solvent-exposed iron-sulfur clusters" - general oxygen toxicity mechanism across anaerobes.
• molecular oxygen inactivates glycyl radical enzymes

  Glycyl radical enzymes are inherently incompatible with molecular oxygen.

  • DOI:10.1128/iai.00502-24 "Certain enzyme classes (e.g., glycyl radical enzymes) are inherently incompatible with molecular oxygen" - broad across taxa.
• molecular oxygen inactivates low-potential energy-metabolism enzymes (PFOR/PFL)

  Key anaerobic energy-metabolism enzymes (PFOR, PFL) with low-potential Fe-S clusters are oxygen sensitive.

  • DOI:10.1038/s43705-023-00251-7 "key enzymes involved in energy metabolism in anaerobes such as pyruvate ferrodoxin oxidoreductase (PFOR), pyruvate formate lyase (PFL)... are known to be O2 sensitive" - general anaerobe biology.