D esulfocucumis

Abstract

De.sul.fo.cu'cu.mis. L. pref. de from; L. neut. n. sulfur sulfur; L. masc. n. cucumis cucumber; N.L. masc. n. Desulfocucumis a sulfate‐reducing cucumber‐shaped bacterium. Firmicutes / Clostridia / Clostridiales / Desulfocucumaceae / Desulfocucumis Cells are curved rod to vibroid. Gram‐stain‐negative. Spherical spores occur at cell terminals without clear swelling sporangium. Motile with peritrichous flagella. Strictly anaerobic, having a respiratory type of metabolism. Mesophilic and neutrophilic. NaCl is not required for growth. Chemolithoautotroph or chemoorganoheterotroph using organic acids, yeast extract, and alcohols. The substrates are oxidized to CO 2 via the anaerobic C 1 ‐pathway (carbon monoxide dehydrogenase or Wood–Ljungdahl pathway). Addition of yeast extract enhances the growth on acetate, but it is not required for growth. H 2 can serve as the electron donor and CO 2 as the carbon source. Sulfate, thiosulfate, and elemental sulfur are used as electron acceptors and reduced to sulfide; sulfite, nitrate, nitrite, and Fe (III) are not utilized. Grows fermentatively on organic acids but not on sugars. Desulfoviridin is absent. Major cellular fatty acids are iso‐C 15 : 0 , iso‐C 17 : 0 , and C 17 : 0 cyclopropane. Major menaquinone is MK‐7. Found in marsh soil. DNA G + C content (mol%) : 46.6 (LC); 49.1 (genome). Type species : Desulfocucumis palustris Watanabe, Kojima and Fukui 2017, 2681 VP .