180 



ORDER I. PSEUDOMONADALES 



Gelatin: No liquefaction. 



Milk: Growth, but no visible change in 

 the milk. 



No growth with ammonium salts, nitrates 

 or asparagine as a source of nitrogen. 



No growth in peptone water without 

 carbohydrates. Invertase secreted. 



Starch not hj'drolyzed. 



Temperature relations: Optimum, about 

 25° C. Maximum, 37° C. 



Distinctive characters: Differs from 

 Xanthomonas vasculorum, which produces a 

 large gummy type of colony and which is 

 a very active organism biochemically. The 

 two pathogens also differ in the type of 

 lesion they produce on sugar cane. 



Source : Isolated by D. S. North (Colonial 

 Sugar Ref. Co., Sydney, N. S. Wales, Agr. 

 Rept., 8, 1926, 1) from white stripe and leaf 

 scald of sugar cane in Australia. 



Habitat: Vascular pathogen of sugar 

 cane, Saccharum officinarum. 



Group II. — Saprophytic species. 



4. Pseudomonas trifolii Huss, 1907. 

 (Huss, Cent. f. Bakt., II Abt., 19, 1907, 68; 

 Xanthomonas trifolii James, Canadian Jour. 

 Microbiol., 1, 1955, 479.) 



tri.fo'li.i. L. trifoUum trefoil, clover; 

 M.L. neut.n. TrifoUum generic name of 

 clover; M.L. gen. noun trifolii of TrifoUum. 



Rods, 0.5 to 0.7 by 0.75 to 2.0 microns, 

 occurring singly, in pairs and in chains. 

 Motile, possessing a single polar flagellum. 

 Gram-negative. 



Gelatin colonies: Convex, smooth, moist, 

 glistening, grayish yellow. 



Gelatin stab: Napiform liquefaction. 



Agar colonies: Small, circular, grayish, 

 becoming brownish yellow. 



Agar slant: Yellowish, becoming brown- 

 ish yellow streak, lacerate margin. 



Broth: Turbid, with grayish yellow pel- 

 licle and sediment. 



Litmus milk: Slowly coagulated; alkaline; 

 with yellow ring. 



Potato: Thick, yellowish, fiat, smooth, 

 glistening. 



Hydrogen sulfide produced. 



Indole produced. 



Acid from glucose, sucrose, xylose, arabi- 

 nose and mannitol. No acid from lactose. 



Nitrites produced from nitrates. 



Cultures have an agreeable odor. 



Volutin formed. 



Aerobic, facultative. 



Optimum temperature, between 33° and 

 35° C. 



Source: Isolated from clover hay. 



Habitat: Evidently a common organism 

 on the leaves of plants. 



5. Pseudomonas xanthe Zettnow, 1916. 

 Cent. f. Bakt., I Abt., Orig., 77, 1916, 220.) 



xan'tha. Gr. adj. xanthus yellow. 



Rods 0.5 to 0.6 by 0.4 to 1.4 microns. 

 Motile, possessing a single or occasionally 

 two or more very long (20 microns) polar 

 flagella. Gram-negative. 



Gelatin colonies: Circular, yellow, granu- 

 lar. 



Gelatin stab: Pale yellow surface growth. 

 Brownish j^ellow under surface colonies. 

 Saccate liquefaction. 



Agar slant: Dark yellow, glistening, with 

 dark yellow sediment in water of condensa- 

 tion. Pigment not water-soluble. 



Broth: Turbid. 



Milk becomes rose-yellow in 4 weeks with- 

 out anj^ other change. 



Potato: Grayish yellow to brownish 

 growth. 



Indole produced. 



Nitrites produced from nitrates. 

 Acid produced from glucose, sucrose and 

 maltose. 



Starch hydrolyzed. 



Blood serum not liquefied. 



Aerobic, facultative. 



Optimum temperature, 30° C. 



Source: Air contamination. 



6. Pseudomonas caudata (Wright, 

 1895) Conn, 1919. (Bacillus caudatus Wright, 

 Memoirs Nat. Acad. Sci., 7, 1895, 444; 

 Conn, Jour. Agr. Res., 16, 1919, 313.) 



cau.da'ta. L. noun canda a tail; M.L. adj. 

 caudatus having a tail. 



Rods long, granular, slender, occurring 

 singly, in pairs and in chains. Appear like 

 cocci in old cultures. Motile, possessing a 

 polar flagellum (Conn). Gram-negative. 



Gelatin colonies: Yellow, translucent, 

 smooth, undulate. 



Gelatin stab: Villous growth in stab. 

 Crateriform liquefaction. 



