Protoaerobes

The Evolution of Protoaerobic and Aerobic Prokaryote Chemotypes (Three to Two Billion Years Ago)... 

The Employment of Metal Ions in Protoaerobes and the Special Cases... 

The handling of sulfate by protoaerobes depends upon the initial energised coupling to adenosine phosphate as APS, since sulfate is difficult to reduce. The reductase is a flavoprotein linked to Fe S electron transfer centres. Subsequently, released sulfite is reduced by a haem protein (SIR) in which haem is directly bound... 

From this account of the protoaerobic and aerobic prokaryotes it is clear that the change of the environment from a moderately reducing to an oxidising environment with the need to maintain the reductive metabolism of the cell cytoplasm placed a burden on what was possible for these small cells. We describe another way round these problems other than protected cytoplasmic reactions before we discuss the extra problems of controlling the new activities. 

Bacteria Different membrane lipids and coenzymes (a) Strict anaerobes non-photosynthesising (b) Sulfate, ferric iron, and later nitrate users protoaerobes (c) Photosynthesisers extra Mg, release 02 (d) Aerobes utilising Cu, 02 reactions giving new organic products... 

Much of (1) to (8) was managed in what we have called protoaerobes, which was followed on increase of aerobic conditions by ... 

From this account of prokaryotes it must be clear that the switches from anaerobic to protoaerobic and then to aerobic chemotypes amongst prokaryotes was not a gain in intrinsic cellular efficiency in the processes of fast reproduction and survival... 

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