Module 10: Metabolisms

• methanogens are obligate anerobes
• what habitats are methanogens found in?

  • anoxic sediments
  • deep sea vents
  • animal digestive tracts
• methanogenesis is anaerobic respiration
• what is the e- donor and e- acceptor in methanogenesis?

  e- donor: H2

  e- acceptor: CO2, reduced to methane
• how does methanogenesis produce ATP?

  generates proton or sodium motive force, e- carrier is methanophenazine
• acetogens are anaerobic bacteria, typically firmicutes
• what is the e- acceptor and pathway of acetogens?

  Co2 e- acceptor is reduced to acetate in acetyl-coA pathway
• when are methanogens favored over acetogens?

  low CO2 or cobalt
• when are acetogens favored over methanogens?

  in higher nutrient solutions