SUBSTRATA MAIN PAGE|
TAXONOMY: Bacteria -> Terrabacteria group -> Firmicutes -> Clostridia -> Clostridiales -> Clostridiaceae -> Sarcina
Sarcina is a genus of Gram-positive cocci bacteria in the family Clostridiaceae. A synthesizer of microbial cellulose, they have a cuboidal cell arrangement. Various members of the genus are human flora and may be found in the skin and large intestine. The genus's type species is Sarcina ventriculi, a variety found on the surface of cereal seeds, in soil, mud, and in the stomachs of humans, rabbits, and guinea pigs. Nearly spherical cells, 1.8–3.0 µm in diameter, occurring in packets of eight or more. Some of the cells in cultures may be present singly, or as groups of fewer than eight cells. Generally the cells are flattened in the areas of contact with adjacent cells. Division occurs in three perpendicular planes. Spore formation by these organisms has been reported (Knöll, 1965; Knöll and R. Horschak, 1971). Gram-stain-positive. Nonmotile. Chemo-organotrophic anaerobes, having an exclusively fermentative metabolism. Relatively aerotolerant. Carbohydrates are the fermentable substrates. The main products of glucose fermentation are CO2, H2, acetic acid as well as ethanol for Sarcina ventriculi and butyric acid for Sarcina maxima. Not pigmented. Catalase-negative. The minimal growth requirements include numerous amino acids and few vitamins, in addition to a fermentable substrate and inorganic salts. Grow at pH values near 1 and up to pH 9.8.
DNA G+C content (mol%): 28–31.
Type species: Sarcina ventriculi