Geochemical and physiological processes mediated by magnetotactic bacteria are not well understood despite the fact that these unusual procaryotes are ubiquitous in and easily collected from aquatic habitats. Preliminary results with several new isolates of magnetotactic bacteria strongly suggest that cells of these strains are involved in the oxidation of reduced sulfur and perhaps iron compounds. Moreover, these results show that these strains can grow with reduced sulfur compounds as sole energy (electron) sources using carbon dioxide as the sole carbon source. Thus, it is likely that these new strains can grow chemolithoautotrophically and perhaps mixotrophically as well. Microbiological, chemical, and biochemical strategies will determine the role of these new strains of magnetotactic bacteria in sulfur and iron cycling and their chemolithoautotrophic potential. The results obtained from this study will be invaluable in understanding the overall physiology of magnetotactic bacteria, in ascertaining the geochemical roles magnetotactic bacteria play in nature, in the isolation of new strains, and ultimately in how they synthesize their magnetic mineral component.
