FAMILY XII. CORYNEBACTERIACEAE 



607 



2. No growth on plain agar; brownish yellow pigment produced on soil-extract agar; 

 gelatin not liquefied; no growth at 10° C. 



9. Arthrobacler terregens. 



1. Arlhrobacter globiforniis (Conn, 

 1928) Conn and Dimmick, 1947. (Bacterium 

 globiforme Conn, New York Agr. Exp. Sta. 

 Tech. Bull. 138, 1928, 3; also see Conn and 

 Darrow, ibid., 172, 1930, 3; Arthrobacler 

 globiforme (sic) Conn and Dimmick, Jour. 

 Bact., 54, 1947, 295, Fig. 1, and 301.) 



glo.bi.for'mis. L. noxxnglobus ball, globe; 

 L. novLD. foryna shape; M.L. adj. globijormis 

 spherical. 



Rods, irregular in shape and size, gen- 

 erally 0.5 to 0.7 by 1.0 to 3.0 microns, oc- 

 curring in an angular arrangement. Cells 

 may be curved, slightly bent or, frequently, 

 swollen; rudimentary branching may occur 

 in liquid media. Coccoid cells, 0.6 to 0.8 mi- 

 cron in diameter, develop in older cultures; 

 larger coccoid cells (cjstites) occur which 

 give rise to rod forms by germination on 

 transfer to fresh media. Non-motile. Gram- 

 negative in young cultures; coccoid forms 

 prevailingly Gram-positive. 



Gelatin stab: Slow crateriform liquefac- 

 tion, becoming stratiform; liquid clear; 

 abundant sediment. 



Agar colonies: Circular, up to 1.5 mm in 

 diameter, slightl}' raised, cream-colored, 

 waxy luster. 



Agar slant: Growth filiform, flat, smooth, 

 cream-colored, soft glistening with metallic 

 sheen. 



Soil extract agar slant: Growth filiform, 

 flat, pale cream-colored, surface slightly 

 rippled, soft, translucent, glistening, no 

 sheen, lobate edge. 



Asparagine agar slant: Filiform, flat, 

 smooth, whitish, dull, soft. 



Broth: Slightly turbid; little or no surface 

 growth; slight sediment. 



Potato: Growth abundant, pale brown, 

 glistening, soft. 



Milk: Slow clearing (2 to 3 weeks) without 

 coagulation; alkaline. 



Indole not produced. 



Hydrogen sulfide produced in small 

 amounts in cysteine medium. 



Slight acid but no gas from glucose, su- 

 crose, mannitol and arabinose; no acid or 

 gas from lactose or glycerol. 



Acetylmethylcarbinol not produced. 



Starch is hydrolj-zed. 



Nitrites produced from nitrates. 



Urease not produced. 



Utilizes nitrates and ammonium salts as 

 nitrogen sources; citrates utilized as sole 

 source of carbon. 



Of 19 amino acids tested, none was re- 

 quired for growth; preformed growth factors 

 also were not required (Campbell and Wil- 

 liams, Food Research, 16, 1951, 506). 



Ammonium chloride and the 19 amino 

 acids which were tested may serve as sources 

 of nitrogen; the amino acids may also be 

 utilized as carbon sources (Campbell and 

 Williams, loc. cit.). 



Inorganic sulfur may serve as a source of 

 sulfur (Campbell and Williams, loc. cit.). 



Catalase-positive. 



Aerobic. 



Temperature relations: Optimum, about 

 25° C; good growth from 20° to 32° C; 

 slight growth at 10° C; no growth at 37° C. 



Source: Isolated from soil. 



Habitat: Widely distributed in soil. 



2. Arthrobacler pascens Lochhead and 

 Burton, 1953. (Can. Jour. Botany, 31, 

 1953, 7.) 



pas'cens. L. part. adj. -pascens nourishing. 



Rods, generally 0.6 to 0.8 by 1.0 to 4.0 

 microns, occurring in an angular arrange- 

 ment as a result of snapping division. The 

 cells vary in size and shape according to the 

 culture medium: irregular forms, curved, 

 swollen or club-shaped, may be noted as 

 well as a tendency to form short filaments 

 with rudimentary budding, especially in 

 liquid media. Coccoid cells occur by the 

 process of fragmentation, usually within 

 two days. On solid media the cocci are 0.5 

 to 0.7 micron in diameter, and 0.7 to 0.9 

 microns in diameter in semisolid or liquid 

 media. On fresh transfer, the large coccoid 

 cells (cystites) germinate and give rise to 

 two or more rod forms. Non-motile. Gram- 

 negative. 



Gelatin stab: White, viscous surface 

 growth followed by slow liquefaction which 



