Habitat: Widel}' distributed in fermenting substances. 14. Lactobacillus brevis (Orla-Jensen, 1919) Bergey et al., 1934. (Bacillus y, von Freudenreich, Landw. Jahrb. d. Schweiz, 1891, 22; Bacillus casei y, von Freudenreich and Thoni, Landw. Jahrb. d. Schweiz, 1904, 526; Beiabacterium breve Orla-Jensen, The Lactic Acid Bacteria, 1919, 175; Bergey et aL, Manual, 4th ed., 1934, 312.) bre'vis. L. adj. brevis short. Description supplemented by material fromPederson (Jour, of Bact.,S5, 1938, 105). Rods, 0.7 to 1.0 by 2.0 to 4.0 microns, with rounded ends, occurring singly, in short chains and occasionally in long filaments which may show granulation. Non-motile. Gram-positive. Gelatin: No liquefaction. Agar slant: Growth, if any, faint. Broth: Turbid, clearing after a few daj^s. Milk: Acid produced but no clot except with some freshly isolated strains. Does not attack casein as a rule. Utilizes calcium lactate as a source of carbon. Acid from arabinose, xylose, glucose, fructose, galactose and maltose. Strains vary in fermentation of lactose, sucrose, mannose and raffinose. Salicin, mannitol, glycerol, rhamnose, dextrin, inulin and starch seldom fermented. Usually shows a particularly^ vigorous fermentation of arabi- nose. Lactic acid produced usually optically inactive; acetic acid, ethyl alcohol and carbon dioxide formed in fermentation of aldohexoses. Mannitol produced from fruc- tose. Acetic and lactic acids produced from the pentoses. Temperature relations: Optimum, 30° C. Growth poor below 15° and above 37° C. Maximum, 38° C. This species includes the large group of gas-producing lactic acid rods ordinarily characterized by a marked fermentation of pentoses, particularly arabinose. Thej^ usu- ally also ferment fructose more readily than glucose. Comment: A chromogenic variety which causes the production of rusty spot in cheese has been described by Davis and Mattick (Proc. Soc. Agr. Bact., 1936, 3) and by Breed and Pederson (Jour. Bact., S6, 1938, 667; also see New York Agr. Exp. Sta. Tech. Bull. 259, 1941, 15 pp.). Source: Isolated from milk, kefir, cheese, feces, fermenting sauerkraut, ensilage, manure, soils, sour dough and spoiled to- mato products. Habitat: Widely distributed in nature, particularly in plant and animal products. 15. Lactobacillus fermenti Beijerinck, 1901. (Arch, n^erl. d. sci. exact, et nat., Ser. 2, 7, 1901, 212.) fer.men'ti. L. neut.n. fermentum ferment yeast; L. gen. noun fermenti of yeast. Description supplemented by material from Smit (Ztschr. f. Garungsphysiol., 5, 1916, 273) and Pederson (Jour. Bact., 35, 1938, 106). Rods, variable in size, usually short (Bei- jerinck), 0.5 to 1.0 by 3.0 to 15.0 microns (Smit), sometimes in pairs or chains. Non- motile. Gram-positive (Smit). Yeast extract-glucose-gelatin: Filiform, no liquefaction (Pederson). Agar colonies: Flat, circular, small, trans- lucent like droplets of water. Agar slant: Growth, if any, scant. Broth: Turbid, clearing after a few days. Milk: Unchanged or slightly acid. Reduction of litmus, methylene blue, indigo carmine, sodium thiosulfate. NaoSOs is reduced to H2S (Smit). Acid usually from glucose, fructose, malt- ose, sucrose and lactose (Beijerinck) and mannose, galactose and raffinose; some strains ferment xylose; usually does not ferment arabinose, rhamnose, sorbitol, mannitol, inulin, dextrin, starch or salicin (Pederson). Lactic acid produced usually optically inactive; acetic acid, ethyl alcohol and carbon dioxide are formed in the fermenta- tion of aldohexoses (Smit), (Pederson). Mannitol is formed in the fermentation of fructose (Beijerinck), (Smit). Acetic acid and lactic acid are produced from pentoses if they are fermented (Pederson). These are the higher temperature gas-
