Desulfococcaceae

Abstract

Abstract De.sul.fo.coc.ca.ce'ae. N.L. masc. n. Desulfococcus , type genus of the family; suff. ‐ aceae , ending to denote a family; N.L. fem. pl. n. Desulfococcaceae , the family of Desulfococcus . Desulfobacterota / Desulfobacteria / Desulfobacterales / Desulfococcaceae Cells are oval to lemon shaped and occur singly, in pairs, or as multicellular filaments. Gram‐stain‐negative. Endospores are not observed. Motility is restricted to filaments by gliding, and other forms are nonmotile. Strict anaerobes with a respiratory type of metabolism. Chemoorganoheterotrophic. Simple organic compounds such as formate, fatty acids, dicarboxylic acid, or aromatic compounds (some species) serve as sole electron donors and carbon sources and are oxidized to CO 2 via the anaerobic C 1 ‐pathway (carbon monoxide dehydrogenase [CODH] or Wood–Ljungdahl pathway). Chemolithoautotrophic growth on H 2 and CO 2 might occur. Sulfate and often also sulfite and thiosulfate serve as terminal electron acceptors and are reduced to sulfide. Fermentation of organic compounds is restricted to the genus Desulfococcus . Mesophilic. The major menaquinones are MK‐7 and MK‐9. Desulfoviridin is only present in the genus Desulfonema . Cytochromes of the c type might occur. The family currently accommodates two genera. Members of this family are found in anoxic sediments of freshwater, brackish water, and marine systems. DNA G + C content (mol%) : 38.2–58.3 ( T m , LC, genome). Type genus : Desulfococcus Widdel 1981 VP (Effective publication: Widdel 1980).