608 



ORDER IV. EUBACTERIALES 



becomes stratiform; liquid flaky; abundant 

 sediment. 



Agar colonies: Circular, entire, creamy 

 white, glistening, translucent, viscous. 



Agar slant: Growth filiform, flat, smooth, 

 viscous, cream-colored, glistening with a 

 copper sheen. 



Soil extract agar slant: Growth filiform, 

 flat, smooth, cream-colored, glistening, 

 slightly metallic, soft. 



Asparagine agar: Abundant, filiform, 

 cream-colored, very viscous growth; edge 

 wrinkled, surface smooth and glistening. 



Broth: Moderately turbid; no surface 

 growth; whitish, viscous sediment. 



Potato: Pale brown, glistening, viscous. 



Milk: Slow clearing after 1 week without 

 coagulation; abundant, white surface 

 growth; reaction becoming alkaline. 



Indole not produced. 



Hydrogen sulfide produced in cysteine 

 medium. 



Slight acid but no gas from glucose and 

 sucrose. 



Acetylmethylcarbinol not produced. 



Starch is hydrolyzed. 



Nitrites produced from nitrates. 



Urease not produced. 



Utilizes nitrates and ammonium salts as 

 nitrogen sources; citrates utilized as sole 

 source of carbon. 



Catalase-positive. 



Aerobic, facultatively anaerobic. 



Temperature relations: Optimum, be- 

 tween 20° C. and 26° C.; growth range, 10° 

 to 35° C.; no growth at 37° C. 



Source: Isolated from soil. 



Habitat: Soil. 



3. Arthrobacter simplex (Jensen, 1934) 

 Lochhead, comb. nov. {Corynebactenum 

 simplex Jensen, Proc. Linn. Soc. New So. 

 Wales, 59, 1934, 43.) 



sim'plex. L. adj. simplex simple. 



Rods which vary in size with the culture 

 medium, generally 0.4 to 0.5 by 1.0 to 3.0 

 microns; occasionally cells may attain a 

 length of 6.0 microns. In older cultures the 

 cells are shorter and become very small 

 rods or cocci, measuring 0.4 to 0.5 by 0.5 to 

 0.8 micron. Though curved or swollen rods 

 generally tend to be inconsistent in form, 

 the tendency is less pronounced with this 



species. Generally non-motile; motile 

 strains have been reported (Clark and Carr, 

 Jour. Bact., 6£, 1951, 3 and 4). Gram-vari- 

 able; coccoid cells are Gram-variable with 

 a predominance of Gram-positive cells. 



Gelatin stab: Saccate liquefaction (2 to 

 4 days) becoming stratiform; slight surface 

 growth; considerable sediment; liquid clear. 



Agar colonies: Circular, 1.0 to 1.5 mm in 

 diameter, slightly raised, cream-colored, 

 smooth, glistening. 



Agar slant: Growth filiform, cream-col- 

 ored, smooth, glistening, soft; lobate edge. 



Soil extract agar slant: Growth filiform, 

 flat, pale cream-colored, smooth, glistening, 

 translucent, soft. 



Asparagine agar slant: Growth filiform, 

 flat, pale cream-colored, smooth, glistening, 

 soft. 



Broth: Moderately turbid; no surface 

 growth; moderate, stringy sediment. 



Potato: Growth abundant, light brown, 

 moist, glistening, membranous. 



Milk : Slow clearing (7 to 10 days) without 

 coagulation, becoming alkaline. 



Indole not produced. 



Hydrogen sulfide produced in cysteine 

 and thiosulfate media. 



Sugar media: Slight alkaline reaction; no 

 gas produced. 



Acetylmethylcarbinol not produced. 



Starch not hydrolyzed. 



Nitrites produced from nitrates. 



Urease not produced. 



Utilizes nitrates and ammonium salts as 

 nitrogen sources; citrates utilized as sole 

 carbon source. 



Catalase-positive. 



Aerobic. 



Temperature relations: Optimum, be- 

 tween 26° and 37° C; no growth at 10° or 

 45° C. 



Source: Isolated from Australian soil. 



Habitat: Soil. 



4. Arthrobacter oxydans Sguros, 1954. 

 (Proc. 54th Gen. Meeting, Soc. Amer. Bact., 

 Pittsburgh, 1954, 21.) 



ox'y-dans. Gr. adj. oxys sharp; M.L. adj. 

 oxydans oxidizing. 



Complete description furnished by Dr. 

 P. L. Sguros. 



