Desulfitobacterium

Abstract

De.sul.fi.to.bac.te'ri.um. L. pref. de from, off, away; N.L. n. sulfis sulfite; N.L. masc. n. bacter rod; N.L. neut. n. Desulfitobacterium rod‐shaped bacterium that reduces sulfite. Firmicutes / “Clostridia” / Clostridiales / Peptococcaceae / Desulfi tobacterium Cell wall is of Gram‐positive structure but may stain Gram‐negative or ‐positive depending on the strain. Exponential‐growth phase cells are straight or curved rods , 2–5 µm in length, depending on the species and strain. Although the physiology is obligately anaerobic; certain species tolerate microaerophilic culture conditions (<5% air in N 2 head gas phase); mesophilic and heterotrophic . Desulfitobacterium species use a variety of chlorinated phenols and/or alkenes as electron acceptors during dehalorespiration (also called halorespiration or chloridogenesis). Furthermore, they reduce sulfite, thiosulfate, sulfur, fumarate (forming succinate), and nitrate, but not sulfate, in the presence of various electron donors. Yeast extract as growth supplement is required; some strains grow only using pyruvate (forming lactate + acetate + CO 2 ), others can utilize various sugars. Four species are validly published, Desulfitobacterium dehalogenans , Desulfitobacterium chlororespirans , Desulfitobacterium hafniense , and Desulfitobacterium metallireducens . For differentiation of the species, see Table 181. DNA G + C content ( mol %): 45–48.8. Type species : Desulfitobacterium dehalogenans Utkin, Woese and Wiegel 1994, 615 VP .