Page:Bergey's manual of determinative bacteriology.djvu/125

 pairs and in chains. Motile, possessing a single polar flagellum. Gram-negative.

Gelatin colonies: Circular, white, translucent. Dark centers with a greenish shimmer, thinner edges and faint radial lines.

Gelatin stab: Crateriform liquefaction.

Agar slant: Grayish white, glistening. Agar becomes green.

Broth: Turbid; delicate pellicle; white sediment. Becomes green.

Litmus milk: Acid, coagulated; litmus reduced.

Potato: Raised, granular, spreading, viscid. Becomes brownish.

Indole produced.

Action on nitrates unknown.

Aerobic, facultative.

Optimum temperature, 20° to 25° C. Fails to grow at 35° C.

Source: From water from the Schuylkill River.

Habitat: Water.

9. Pseudomonas chlororaphis (Guignard and Sauvageau, 1894) Bergey et al. 1930. (Bacillus chlororaphis Guignard and Sauvageau, Compt. rend. Soc. Biol., Paris. 1, 10 sér., 1894, 841; Bergey et al.. Manual 3rd ed., 1930, 166.)

chlo.ro′ra.phis. Gr. chlorus green; Gr noun rhaphis a needle; M.L. fem. n. chlororaphis a green needle.

Description taken from Lasseur (Ann. de la Sci. Agron., Sér. 4, 2e Année, 2, 1913, 165). While Guignard and Sauvageau (op. cit. 1894, 841) found spores in this species, Gessard, on reisolation, could find no spores (Ann. de la Sci. Agron., Sér. 3, 6e Année, 2, 1911, 374). The identification of the reisolated culture was confirmed by Guignard The original description is brief and inadequate and is probably based on a contaminated culture.

Rods, 0.8 by 1.5 microns, with rounded ends, occurring singly and in pairs. Motile with one to six polar flagella. Gram-negative. After continued cultivation some cells decolorize slowly.

Gelatin colonies: Circular, viscid, transparent, glistening, lobate margin with fluorescent corona. Dissociates readily (Lasseur and Dupaix-Lasseur, Trav. Lab. Microbiol. Fac. Pharm. Nancy, Fasc. 9, 1936, 35).

Gelatin stab : Rapid liquefaction. Fluorescent. Chlororaphine crystals may form.

Broth: Turbid, greenish, fluorescent. Crystals of green chlororaphine may form. Broth becomes viscous.

Litmus milk: Alkaline; coagulated. Becomes viscous. Chlororaphine crystals may form in the central part of the culture. Odor of coumarin.

Potato: Citron-yellow layer. Crystals of chlororaphine are formed.

Nitrites produced from nitrates.

Indole not produced.

Pigment formation: Asparagine, potassium phosphate, glycerol, sulfate of magnesium and sulfate of iron are indispensable to the formation of crystals of chlororaphine. Green crystals develop slowly and poorly in peptone solutions, best in synthetic media.

Aerobic, facultative.

Optimum temperature, between 25° and 30° C. Cultures killed in ten minutes at 63° C.

Pathogenic for mice, guinea pigs, frogs, fresh-water fishes and crayfishes. An exotoxin is formed.

Distinctive character: Produces a beautiful emerald-green pigment which crystallizes in cultures as fine needles in bundles or as needles radiating from a center. The crystals form slowly and are not always present. Other species of pseudomonads, e.g. Pseudomonas iodinum, form crystals. As this power is readily lost, it raises the question whether other species of green, fluorescent pseudomonads may not form crystals under proper conditions.

Source: Isolated from dead larvae of the cockchafer. Later reisolated by various French bacteriologists from contaminated water supplies.

Habitat: Decomposing organic matter and fresh water so far as known.

10. Pseudomonas myxogenes Fuhrmann, 1907. (Cent. f. Bakt., II Abt., 17, 1907, 356.)

myx.o′ge.nes. Gr. myxa slime; Gr. gennao to produce, beget; M.L. adj. myxogenes slime-producing.