Cells 1.0 micron wide at the center by 6 to 8 microns long. Except for size, very similar to those of Cyfophnga hutchinsonii. Gram-negative. Produces orange, mucilaginous patches on filter paper-silica gel plates. Fibrolysis is very rapid and intense. Source: Isolated from soil. Habitat: Soil. Decomposes cellulose. 4. Cytophaga rubra Winogradsky, 1929.
- Ann. Inst. Past., 43, 1929, 598.)
ru'bra. L. adj. ruber red. Description taken from Stanier (Bact. Rev., 6, 1942, 192). Flexible, singly occurring rods, 0.5 to 0.7 by 3.5 to 11.0 microns, averaging about 7.0 microns in length. Gram-negative. Produces diffuse, bright pink, rapidly spreading patches on filter paper-silica gel or -agar plates after a few days. The patches are onlj- slightly mucilaginous, and dissolu- tion of the fibers always remains incomplete. Produces small, pale pink, translucent colonies with hazily defined peripheries on mineral-glucose-agar plates. The maximum diameter is 2 mm, and the colonies are sunken in the medium. Cellulose, cellobiose, glucose, mannose and xylose are utilized. Arabinose, galac- tose, fructose and mannitol are not uti- lized. Ammonia, nitrate, aspartic acid, aspara- gine, peptone and yeast extract can serve as nitrogen sources. Catalase-positive. Strictly aerobic. Optimum temperature, 30° C. Source: Isolated from soil. Habitat: Soil. Decomposes cellulose. 5. Cytophaga tenuissima Winogradsky, 1929. (Ann. Inst. Past., 43, 1929, 599; in- correctly spelled Cytophaga iernissima in Bergey et al.. Manual, 4th ed., 1934, 559.) te.nu.is'si.ma. L. sup. adj. tenuissimus very slender. Dimensions of cells not given, but de- scribed as being extremely slender. Gram- negative. Produces mucilaginous, greenish to olive patches on filter paper-silica gel plates. Source: Isolated from soil. Habitat: Soil. Decomposes cellulose. 6. Cytophaga johnsonii Stanier, 1947. (Vegetative myxobacteria, Johnson, Jour. Bact., £4, 1932, 340; Stanier, Jour. Bact., 53, 1947, 306.) john.so'ni.i. M.L. gen. noun johnsonii of Johnson; named for Miss Delia E. Johnson, the bacteriologist who first isolated this species. Thin rods of even width and very variable length. Dimensions 0.2 to 0.4 by 1.5 to 15.0 microns. Long rods predominate in very young cultures, but in most strains they give place to shorter, sometimes almost coccoid, elements as cultures age. Gram- negative. Growth on peptone agar is smooth, glis- tening, translucent and bright yellow. Col- ony form markedly modified by peptone concentration. With low concentrations, a characteristically myxobacterial colony: thin, flat and rapidly spreading; with more than 0.5 per cent peptone: raised, convex and confined, with entire edge. Growth on chitin agar is flat, rapidly spreading, translucent, pale yellow, accom- panied by dissolution of the suspended chitin. Peptone gelatin: Scanty growth, followed by very slow liquefaction. Some strains do not grow. Milk: Very slow peptonization. Arabinose, xylose, glucose, galactose, mannose, lactose, sucrose, cellobiose, malt- ose, raffinose, starch, inulin and chitin are utilized. Cellulose, mannitol and dulcitol are not utilized. Peptone and other complex nitrogenous materials can serve as carbon sources in the absence of carbohydrates. Nitrate, ammonia and peptone are suit- able nitrogen sources. Catalase not formed. Indole not produced. Nitrate usually not reduced. One variety is capable of denitrification with a vigorous gas production from nitrate. Strictly aerobic. Optimum temperature, between 25*^ and 30° C. Source: Isolated from soil and mud. Habitat: Soil. Decomposes chitin.
