FAMILY PSEUDOMONADACEAE 



109 



Acid from glucose, maltose, sucrose 

 and mannitol but not from lactose or 

 glycerol. 



Starch hydrolyzed. 



Ammonia liberated from peptone but 

 .no hydrogen sulfide produced. 



Indole formed in tryptophane sea water 

 broth. 



Nitrites produced from nitrates. 



Optimum temperature 20 to 25°C.; 

 30°C. incubation will kill recently isolated 

 organisms. 



Aerobic, facultative. 



Source : Isolated from diseased kilifish 

 (Fundulvs parvipinnis) . 



Habitat : Skin lesions and muscle tissue 

 of infected marine fish. 



58. Pseudomonas nigrifaciens White. 

 (Scientific Agriculture, W, 1940, 643.) 

 From Latin viger, black and faciens, 

 making. 



Rods: 0.3 to 0.7 by 1 to 5 microns, oc- 

 curring singly or in pairs, and having 

 rounded ends. Actively motile, with a 

 single polar flagellum. Gram-negative. 



Gelatin stab : Pigmented surface growth 

 after 24 hours. Slight crateriform lique- 

 faction changing to saccate. 



Agar colonies: Circular, convex, 

 smooth, glistening, entire, 2 to 4 mm in 

 diameter. Slight fluorescence in earl}- 

 stages. The medium assumes a brownish 

 color. 



Agar slant : Growth filiform, smooth, 

 moist, glistening, with blackish pigmenta- 

 tion at 4° and 15°C. in 48 hrs., the medium 

 turning brownish. Slight fluorescence in 

 early stages. 



Broth: Turbid after 24 hours. .A.fter 

 5 to 6 days a black ring and then a pellicle 

 forms, later a black sediment. Medium 

 turns brown. 



Litmus milk : A black ring appears 

 after 3 days at 15°C. followed by a pellicle. 

 Litmus is reduced. Alkaline reaction. 

 No coagulation. Digested with a putrid 

 odor. 



Indole not formed. 



Nitrites not produced from nitrates in 

 7 days. No gas produced. 



iStarch is hydroh'zed. Natural fats 

 not hydrolyzed. 



Alkaline reaction produced in sucrose, 

 maltose, lactose, glucose, mannitol and 

 raffinose broth (pH 8.2). No gas pro- 

 duced. 



Ammonia produced in peptone broth. 



Aerobic. 



Optimum pH 6.8 to 8.4. 



Temperature relations: Minimum 4°C. 

 Optimum 25°C. Ma.ximum 33-35°C. 



Distinctive characters : No or slow 

 growth in culture media in the absence of 

 salt. Maximum growth and pigmenta- 

 tion appeared with 1.5 and 2.5 per cent 

 salt. Optimum pigmentation occurs at 

 4" and 15°C. 



Source : Several cultures isolated from 

 samples of discolored butter. 



Habitat : Causes a black to reddish- 

 brown discoloration of print butter. 

 Evidently widely distributed in nature. 



59. Pseudomonas beijerinckii Hof. 



(Travaux botaniques neerlandais, S2, 

 1935, 152.) Named for M. W. Beijerinck, 

 Dutch bacteriologist . 



Small rods: Motile with polar flagella. 



Gelatin: No liquefaction. 



Indole not formed. 



Nitrites produced from nitrates by 

 four out of six strains. 



Cellulose not decomposed. 



Acid from glucose. In yeast-water 

 with 2 per cent glucose and 12 per cent 

 NaCl no gas is produced. 



Pigment production : Insoluble purple 

 pigment produced but not in all media; 

 is localized markedly; reduced oxygen 

 tension necessary; optimum pH 8.0; not 

 produced in yeast-water or in peptone- 

 water; produced only when grown in 

 extracts of beans or some other vegetable. 



Aerobic. 



Source : Six strains isolated from beans 

 preserved with salt. 



Habitat: Causes purple discoloration 

 of salted beans. 



