Abstract
A.cid.a.min.o.coc'cus. L. n. acidum acid; N.L. neut. n. amino amino; Gr. n. kokkos a grain, berry; N.L. masc. n. Acidaminococcus the amino acid coccus.
Firmicutes / “Clostridia” / Clostridiales / Veillonellaceae / Acidaminococcus
Cells coccoid, 0.6–1.0 µm in diameter, often occurring as oval or kidney-shaped diplococci. Nonspore-forming. Gram-stain-negative. Nonmotile; flagella are not present. The cellwall contains meso -diaminopimelic acid; whole cells contain galactose, glucose, and ribose. Menaquinones and ubiquinones are absent. Anaerobic; no growth on the surface of agar media incubated in the air. Optimal growth at 30–37°C and pH 7.0. Oxidase and catalase-negative. Chemo-organotrophic: D- and L-Glutamate, trans-aconitate, and citrate are the known energy sources. Other amino acids, pyruvate, lactate, fumarate, malate, and succinate are not used as energy sources. Approximately 40% of the strains catabolize glucose, from which little acid is produced. On complex media, ammonia, CO2, acetate, butyrate, and hydrogen are produced, but propionate and valerate have not been detected. Glutamate is fermented to about 1.0 CO2, 1.0 ammonia, 1.2 acetate, 0.4 butyrate, and up to 10 kPa H2; citrate and trans-aconitate are fermented to about 2.0 CO2, 1.8 acetate, 0.1 butyrate, and 90 kPa H2. Nutritional requirements are complex. Isolated from the intestinal tract of the pig and humans. Has also been isolated from cattle rumen, but not usually a predominant ruminal bacterium.
DNA G+C content (mol%): 54.7–57.4.
Type species: Acidaminococcus fermentans Rogosa 1969, 765AL emend. Cook, Rainey, Chen, Stackebrandt and Russell 1994a, 577.
