860 



ORDER VIII. MYXOBACTERALES 



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. 



