202 General Microbiology II

Metabolic Diversity

• Phototrophy 

    

  • light reactions
    • antenna pigments

    • anoxygenic photosynthesis

    • oxygenic photosynthesis

    • reaction center pigments

    • anoxygenic photosynthesis

    • oxygenic photosynthesis

    • photosystem II (PSII):

    • photosystem I: (PSI)

    • ATPsynthase

    • anoxygenic photosynthesis

    • oxygenic photosynthesis

    • cytochrome oxidase

    • anoxygenic photosynthesis

    • oxygenic photosynthesis

  • dark reactions
    • Calvin cycle ... carbon dioxide fixation:

    • overall stoichiometry:

    • unique enzymes

    • reductive (reverse) TCA cycle ... carbon dioxide fixation

    • overall stoichiometry

    • unique enzyme is citrate lyase

    • energy storage as carbohydrate

• Lithotrophy 
  •  
  • oxidizing bacteria
    • general metabolic characteristics

    • ATP generation

    • NADH/NADPH generation

    • carbon dioxide fixation

    • hydrogen-oxidizing bacteria (Alkaligenes, Aquaspirillum, Arthrobacter, Pseudomonas)
    • sulfur-oxidizing bacteria (Beggiatoa, Sulfolobus, Thiobacillus)
    • iron-oxidizing bacteria (Sulfolobus, Thiobacillus ferrooxidans)
    • nitrifying bacteria

    • ammonium-oxidizer (Nitrosomonas)

    • nitrite-oxidizer (Nitrobacter)

    • reducing bacteria - many anaerobic, facultative lithotrophs (Desulfovibrio, Desulfomonas, Desulfobacter)

  • Organotrophy
    • fermentation

    • substrate-level phosphorylation-coupled

    • energy-linked membrane-bound ion pump (ATPsynthase) coupled phosphorylation generally involves the fermentation of dicarboxylic acids

    • aerobic respiration - covered in previous courses - review!
    • anaerobic respiration

    • general characteristics

    • assimilative vs. dissimilative metabolism

    • assimilative

    • dissimilative

    • ATP generation

    • facultative vs obligate anaerobes

    • nitrate-reducing bacteria (Pseudomonas denitrificans, Bacillus, Enterics)

    • sulfate-reducing bacteria (Desulfovibrio)

    • carbonate-reducing bacteria and archaea

    • iron and/or manganese-reducing bacteria

    • fumarate reducing bacteria (Wolinella succinogenes, Desulfovibrio gigas, Escherichia coli, Proteus rettgeri)

    • TMAO-reducing bacteria (several facultative aerobes, purple nonsulfur bacteria)

    • DMSO-reducing bacteria (Campylobacter, Escherichia, many other proteobacteria)