Diversity and distribution of hemerythrin-like proteins in prokaryotes.

Hemerythrins are oxygen-binding proteins found in the body fluids and tissues of certain invertebrates. Oxygen is bound at a nonheme iron centre consisting of two oxo-bridged iron atoms bound to a characteristic set of conserved histidine: aspartate and glutamate residues with the motifs H-HxxxE-HxxxH-HxxxxD. It has recently been demonstrated biochemically that two bacterial proteins bearing the same motifs do in fact possess similar iron centres and bind oxygen in the same way.

Methods evaluating vanadium tolerance in bacteria isolated from crude oil contaminated land.

Investigations into bacterial responses to vanadium are rare, and in this study were initiated by isolating cultures from crude oil contaminated soil from Russia and Saudi Arabia. Addition of vanadyl sulphate and vanadium pentoxide created acid conditions in the media whilst sodium metavanadate and sodium orthovanadate produced neutral and alkaline effects, respectively. Buffers were introduced for wider comparison of the sample set treatments and to distinguish between the effects of pH and compound toxicity.