3. Cellfalcicula fusca Winogradsky, 1929. (Ann. Inst. Pasteur, A3, 1929, 622.) fus'ca. L. adj. fuscus dark, tawny. Plump, curved spindles, 0.5 by 1.2 to 2.5 microns, with slightly pointed ends and a central chromatic granule. Motile by means of a single, polar flagellum. Gram-negative. Produces diffuse, brownish, slightly marbled or veined colonies on cellulose silica gel medium. Filter paper streak: Paper becomes a partially transparent, dry, non-mucilagi- nous pellicle adherent to gel. Aerobic, facultative. Optimum temperature, 20° C. Source: Isolated from a pile of old, damp sawdust. Habitat: Probably rotting wood.
Genus VI. Microcyclus Ørskov, 1928.[1]
(Cent. f. Bakt., I Abt., Orig., 107, 1928, 180; also see Riassunti d. Communicazioni, VI Cong. Internaz. d. Microbiol., Roma, 1, 1953, 24.)
Micro. cyc'lus. Gr. adj. micrus small, little; Gr. cyclus round, circle; M.L. mas.n. Microcyclus small circle.
Small, slightly curved, non-motile rods which form a closed ring during growth. These rings grow into bodies which subdivide again into rod-shaped elements as at the beginning. Encapsulated. Attack few sugars and then only slowly. From fresh-water ponds and from soil.
The type species is Microcyclus aquaticus Ørskov.
1. Microcyclus aquaticus Ørskov, 1928. (Cent. f. Bakt., I Abt., Orig., 107, 1928, 180; also see Riassunti d. Communicazioni, VI Cong. Internaz. d. Microbiol., Roma, 1, 1953, 24.) a.qua'ti.cus. L. adj. aquaticus living in water. Very small, slightly curved rods about 1 micron in length. During growth, the rods form closed rings 2 to 3 microns in diameter. The next stage is a body consisting of horse- shoe-shaped halves that are fastened to- gether without visible divisional lines. These halves further subdivide into separate rods ; the rods then form rings and start the cycle of growth all over again. Form and capsule are seen most distinctly with direct agar microscopy and direct India ink agar microscopy. Encapsulated. Non-motile. Gram-negative. Gelatin: No liquefaction in one month. butyrous. This species is not fastidious in its growth requirements, although colonies are small. It grows well on tap-water agar plus 0.5 per cent peptone. No acid from glucose, sucrose, lactose, maltose, adonitol, dulcitol, sorbitol, inosi- tol, rhamnose and salicin. After six weeks, slight acid in arabinose and xylose. Indole not produced. Non-hemolytic. Grows at temperatures between 5° and 30° C. No growth at 37° C. Source: Originally found in the waters of a woodland lake. Later isolated from fresh- water ponds and occasionally from soil. Sturges (Absts. of Bact., 7, 1923, 11) briefly reports the presence of organisms with the same unusual morphology in ham-curing brines. Habitat: Presumably widely distributed in fresh water and in soil. Agar colonies: Round, smooth edges.
Genus VII. Spirillum Ehrenberg, 1832.[2]
(Physik. Abhandl. k. Akad. Wissensch. Berlin, 1832, 38.)
Spi.ril'lum. Gr. noun spira a spiral; M.L. dim.neut.n. Spirillum a small spiral, generic name.
