Sporulation and further nutritional characteristics of Desulfotomaculum acetoxidans

Acetate-oxidizing sulfate-reducing bacteria of the Desulfotomaculum acetoxidans type have been enriched from animal manure, rumen content and dung contaminated freshwater habitats, indicating that they are primarily intestinal bacteria. Sporulation was observed only when acetate was the organic substrate; with butyrate, which allowed faster growth than acetate, spore formation never occurred. The cone-shaped highly refractile areas adjacent to the spores in spore-forming mother cells were shown to be gas vacuoles. Biotin was the only growth factor required by Desulfotomaculum acetoxidans strain 5575 in minimal media with sulfate and acetate or other organic substrates.