Energetic Aspects of CO Oxidation in Desulfovibrio desulfuricans

N. B. Tarasova^*, A. V. Zolotov, and O. E. Petrova

Kazan Institute of Biology, Kazan Research Center, Russian Academy of Sciences, P.O. Box 30, Kazan, 420503 Russia; E-mail: tarasova@sci.kcn.ru

^* To whom correspondence should be addressed.

Received September 10, 1997; Revision received January 13, 1998

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In cell suspension of Desulfovibrio desulfuricans B-1388, oxidation of CO as the only energy source is associated with reduction of SO₄^2-. After a 2-h incubation of cells in 8% CO, 81% of the gas is converted. Oxidation of 1 mole CO results in formation of 0.23 mole H₂S. Intracellular ATP content increases from 2.5 (control) to 8.3 nmoles/mg (during CO conversion). Dinitrophenol inhibits sulfate reduction and CO oxidation. CO dehydrogenase was detected in cytoplasmic and membrane cell fractions (59 and 34%, respectively).

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KEY WORDS: CO oxidation, CO dehydrogenase, H₂S production, ATP generation, sulfate-reducing bacteria, Desulfovibrio desulfuricans

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