obligately aerobic

Edge evidence

• obligately aerobic depends on molecular oxygen RO:0002502

  Obligate aerobic growth depends on oxygen availability.

  • DOI:10.1016/j.celrep.2023.112444 obligate aerobe ... exposed to hypoxia, stops growing Mycobacterium tuberculosis example supports oxygen requirement in an obligately aerobic bacterium.
• terminal respiratory oxidases reduces molecular oxygen METPO:2000017

  Terminal oxidases use oxygen as the respiratory electron acceptor.

  • DOI:10.1016/j.celrep.2023.112444 transfer electrons from the ETC to O2 Supports oxygen reduction by terminal oxidases in an obligate aerobe.
• electron transport chain includes terminal respiratory oxidases biolink:has_part

  Oxygen-dependent respiratory chains terminate in oxygen reductases.

  • DOI:10.1016/j.bbabio.2011.06.016 respiratory quinol:O2 oxidoreductase Review supports terminal oxygen reductases as respiratory chain enzymes.
• terminal respiratory oxidases contributes to proton motive force RO:0002326

  Oxygen reductases contribute to proton motive force generation.

  • DOI:10.1016/j.bbabio.2011.06.016 production of a proton motive force Supports bioenergetic coupling by cytochrome bd oxygen reductases.
• molecular oxygen enables aerobic respiration RO:0002327

  Molecular oxygen enables aerobic respiration.

  • DOI:10.1111/cmi.13338 Aerobic respiration is identified as the main cause of bacterial oxygen consumption.
• absence of oxygen (anoxia) interrupts flux through electron transport chain

  Anoxia interrupts electron flux through the electron transport chain.

  • DOI:10.1128/JB.00797-19 Interrupted flux through the electron transport chain (ETC) due to the absence of oxygen.
• electron transport chain maintains proton motive force

  Electron transport chain flux maintains the proton motive force; anoxic interruption impairs it.

  • DOI:10.1128/JB.00797-19 Obligate aerobes must maintain redox balance and the proton motive force (PMF) despite interrupted flux through the electron transport chain.
• superoxide dismutase activity mitigates superoxide METPO:2007407

  Superoxide dismutase mitigates superoxide stress in aerobes.

  • DOI:10.1016/j.tim.2020.10.001 Aerobes deploy scavenging enzymes (SOD, catalase, other peroxidases).
• catalase / catalase-peroxidase activity mitigates hydrogen peroxide METPO:2007407

  Catalase/catalase-peroxidase mitigates hydrogen peroxide stress in aerobes.

  • DOI:10.1016/j.tim.2020.10.001 Aerobes deploy scavenging enzymes (SOD, catalase, other peroxidases).
• superoxide inactivates Fe-S cluster enzymes

  Superoxide and H2O2 oxidize and inactivate exposed Fe-S cluster enzymes.

  • DOI:10.1016/j.tim.2020.10.001 Rate constants for cluster oxidation given (~1e6 M-1 s-1 for superoxide and ~1e4 M-1 s-1 for H2O2), explaining ROS-defense need in aerobes.