Morphological and metabolic responses to starvation by the dissimilatory metal-reducing bacterium Shewanella alga BrY

The response of the dissimilatory metal-reducing bacterium Shewanella alga BrY to carbon and nitrogen starvation was examined. Starvation resulted in a gradual decrease in the mean cell volume from 0.48 to 0.2 micron 3 and a dramatic decrease in Fe(III) reductase activity. Growth of starved cultures was initiated with O2, ferric oxyhydroxide, Co(III)-EDTA, or Fe(III)-bearing subsurface materials as the sole electron acceptor. Microbially reduced subsurface materials reduced CrO(4)2-. Starvation of dissimilatory metal-reducing bacteria may provide a means of delivering this metabolism to contaminated subsurface environments for in situ bioremediation.