FAMILY IV. PSEUDOMONADACEAE 



183 



Nutrient agar colonies: Small, yellow; 

 surface of the agar pitted or dimpled. After 

 5 days colonies 5 to 7 mm in diameter, 

 orange-yellow, slightly raised, surrounded 

 b.y a depression. 



Nutrient agar slant: Growth heavy, light 

 orange-yellow; consistency of warm butter; 

 edge entire, slightly raised. Shallow de- 

 pression formed on each side of streak. 

 Agar softened beneath growth. 



Nutrient broth: Turbid in 48 hours. Light 

 orange-j'ellow pellicle; considerable, viscous 

 sediment. 



Litmus milk: Alkaline; butter-colored 

 pellicle. Reduction in bottom of tube after 

 10 daj's. No curd. No digestion. 



Potato: Growth moderate, orange-yellow, 

 smooth. No darkening. 



Indole not produced. 



Nitrites not produced from nitrates. 



Starch agar plates not hydrolyzed. 



Utilizes arabinose, galactose, lactose, 

 fructose, maltose, melezitose, raffinose, 

 starch, xj-lose, glucose, mannose, sucrose, 

 pectin, rhamnose, salicin and dextrin. No 

 growth in dulcitol, erythritol, glycerol, 

 sorbitol, mannitol or inulin. 



Temperature relations: Optimum, 28° C. 

 Good growth at 25° C. Moderate growth at 

 20° and at 37° C. No growth at 10° and at 

 42° C. 



Limits of pH: 5.4 to 10.0. 



Aerobic, facultative. 



Distinctive characters: Softens agar; 

 considerable change in viscosity of agar due 

 to this digestion; utilization of ammonium 

 sulfate as nitrogen source. 



Source: Three cultures isolated from an 

 experimental trickling filter receiving 

 creamery wastes. 



Habitat: Probably widely distributed in 

 nature. 



14. Pseudonionas segnis Goresline, 

 1933. (Jour. Bact., 26, 1933, 452.) 

 seg'nis. L. adj. segnis slow, tardy. 



Short rods, 0.2 to 0.3 by 1.0 to 1.2 microns, 

 with pointed ends, occurring singly or in 

 pairs. Motile with a single polar flagellum. 

 Gram-negative. 



Plain gelatin stab: No growth. 



Nutrient gelatin stab: Growth yellow, 

 half-way down stab, best at surface. No 

 liquefaction. 



Nutrient agar colonies: Very small, light 

 yellow surface pitted. After 5 days colonies 

 5 mm in diameter. 



Nutrient agar slant: Growth heavy, 

 orange -yellow, consistency of warm butter; 

 edge entire, slightly raised; slight de- 

 pression formed on each side of growth. 

 Agar softened beneath growth. 



Nutrient broth: Turbid in 48 hours. No 

 pellicle or surface growth. Moderate amount 

 of sediment. Old cultures with a yellow ring 

 at surface and occasionally a loose mem- 

 brane. 



Litmus milk: Slightly alkaline after 10 

 daj's. No reduction. No surface growth. 



Potato: Scant j'ellow-orange growth. No 

 darkening. 



hidole not produced. 



Nitrites not produced from nitrates. 



Hydrogen sulfide not produced. 



Starch not hydrolyzed. 



Arabinose, glucose, galactose, lactose, 

 fructose, maltose, mannose, xylose, sucrose, 

 melezitose and raffinose utilized. 



Temperature relations: Optimum, 28° C. 

 Good growth at 25° C. Moderate growth at 

 20° and at 37° C. No growth at 10° and at 

 42° C. 



Limits of pH: 5.8 to 9.0. 



Aerobic, facultative. 



Distinctive characters: Softens agar; con- 

 siderable change in viscosity of agar due to 

 this digestion. 



Source: Isolated from an experimental 

 trickling filter receiving creamery wastes. 



Habitat: Probably widely distributed in 

 nature. 



Genus III. Acetobacter Beijerinck, 1898.* 



{Acetobacter Beijerinck, quoted from Krai's Sammlung v. Mikroorg., Prague, 1898, 7; 

 Acetobacterium in Ludwig's abstract of Hoyer, Bijdrage tot de kennis van de azijnbacterien, 



* Revised by Dr. Reese H. Vaughn, Univ. of California, Berkeley, California, June, 

 1943, and Davis, California, March, 1954. 



