The genus Desulfotomaculum, which means a sausage (shaped organism) that reduces sulfur compounds, was first described in 1965. It was then that the three initial species (nigrificans, ruminis, and orientis) were characterized by Campbell and Postgate. Since then, nineteen species of Desulfotomaculum have been identified, from a variety of environments. Desulfotomaculum belongs to the family Bacillaceae. All Desulfotomaculum are rod shaped. Many are curved and have rounded ends. D. orientis is a fat curved specimen with rounded ends that measures 1.5 x 5 mm. Similarly, Desulfotomaculum has flagella in a peritrichous arrangement. This gives D. orientis 'tumbling and twisting' mobility. All Desulfotomaculum are gram-negative and produce endospores. D. orientis produces a round spore that is located centrally or paracentrally. It usually causes the cell to swell slightly.
Desulfotomaculum are chemoorgantrophs that practice respiration but are strict anaerobes. Sulfur compounds act as terminal electron acceptors and are reduced to hydrogen sulfide. They do not completely oxidize the organic substrates (lactate and pyruvate for D. orientis); acetate and carbon dioxide are the end products. The electron transport chain includes cytochromes of the protoheme class.
D. orientis grows optimally at 30-37 C but can grow at 42 C. It requires a specialized media including reducible sulfur compounds, lactate, pyruvate, thioglycolate, and other growth factors. On this media, they produce black colonies.
*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.
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