232 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



mann and Neumann (Bakt. Diag., 1 

 Aufl., 2, 1896, 266; also 7 Aufl., 2, 1927, 

 463). Lehmann and Neumann {loc. cil.) 

 also consider Bacillus violaceus laurenti- 

 cus Lustig (Diagnostik der Bakterien des 

 Wassers, 1893, 103) as being identical 

 with Bacterium violaceum. 



Slender rods: 0.8 to 1.0 by 2.0 to 5.0 

 microns, occurring singly and in chains. 

 Motile, with a single flagellum. Gram- 

 negative. 



Gelatin colonies : Circular, gray, entire 

 margin, assuming a violet color in the 

 center. 



Gelatin stab : Infundibuliform lique- 

 faction with violet sediment in fluid. 



Agar colonies : Whitish, flat, glistening, 

 moist, becoming violet. 



Agar slant: Deep, violet, moist, shiny 

 spreading growth. 



Broth: Slightly turbid, with violet 

 ring and ropy sediment. 



Litmus milk: Violet pellicle. Diges- 

 tion. Alkaline. 



Potato : Limited, dark violet growth. 



Loffler's blood serum : Slowly liquefied. 



Indole not formed. 



Nitrites produced from nitrates. 



Acid from glucose and usually from 

 maltose. No acid from lactose or sucrose. 



Aerobic, facultative. 



Optimum, temperature 25° to 30°C. 

 No growth at 37 °C. Slight growth at 

 2° to 4°C. 



Source : Originally grown on slices of 

 cooked potato exposed to air contamina- 

 tion, and incubated at room temperature. 



Habitat : Water. 



2. Chromobacterium ianthinum (Zopf) 

 Holland. {Bacterium ianthinum Zopf, 

 Die Spaltpilze, 2 Aufl., 1884, 62; Bacillus 

 janthinus Fliigge, Die Mikroorganismen, 

 1886, 291 ; Bacieridium ianthinum Schroc- 

 ter, Kryptogamen Flora von Schlesien, 

 3, 1, 1886, 157; Pseudomonas ianthina 

 Migula, Syst. d. Bakt., 2, 1900, 941 ; Pseu- 

 domonas janthina Chester, Man. Determ. 

 Bact., 1901, 317; Holland, Jour. Bact., 5, 

 1920, 222.) From Greek, ianthinus, 

 violet-blue. 



Rods : 0.5 to 0.8 by 1.5 to 5.0 microns, 

 occurring singly. Motile with peritri- 

 chous flagella. Gram-negative. 



Gelatin colonies: Circular, yellow, 

 becoming violet. 



Gelatin stab : White to violet surface 

 growth. Infundibuliform liquefaction. 



Agar colonies : Creamy center, violet 

 margin. 



Agar slant : Yellowish, moist, glisten- 

 ing, becoming deep violet. 



Broth: Turbid, with light violet pel- 

 licle. 



Litmus milk: Slow coagulation with 

 violet cream layer. Litmus decolorized 

 from below. 



Potato : Violet to violet-black, spread- 

 ing growth. 



Indole not formed. 



Nitrites generally not produced from 

 nitrates. 



Acid from glucose. No acid from 

 maltose, lactose and sucrose. 



Aerobic, facultative. 



Optimum temperature 30°C. Grows 

 well at 37°C. No growth at 2 to 4°C. 



Source : Originally grown on pieces of 

 pig's bladder floated on badly contam 

 inated water. 



Habitat : Water and soil. This may 

 be the species that causes a fatal septi- 

 cemia in animals and man. See Chromo- 

 bacterium violaceum manilae. 



3. Chromobacterium amethystinum 



(Chester) Holland. {Bacillus membra- 

 naceus amethystinus Eisenberg, Bakt. 

 Diag., 1891, 421; Bacterium amethystinus 

 Chester, Ann. Rept. Del. Col. Agr. Exp. 

 Sta., 9, 1897, 117; Bacterium membrana- 

 ceus amethystinus Chester, ibid., 13S: 

 Bacillus amethystinus Holland, Jour. 

 Bact., 5, 1920, 217; not Bacillus amethys- 

 tinus Chester, loc. cit., 262; Holland, 

 loc. cit., 222; Bacterium memhranaceum 

 amethystinum Lehmann and Neumann, 

 Bakt. Diag., 7 Aufl., 2, 1927, 463; Bac- 

 teriujn violaceum amethystinum Cruess- 

 Callaghan and Gorman, Sci. Proc. Royal 

 Dublin Society, 21, 1935, 219.) From 

 Greek, bluish-violet, amethyst. 



