FAMILY CORYXEBACTERIACEAE 



393 



Nitrites not produced from nitrates. 



Indole not formed. 



No H2S produced. 



Acid from glucose, sucrose, lactose and 

 glycerol. 



Moderate diastatic action. 



Grows in 5 per cent salt. 



Optimum temperature 23°C. Maxi- 

 mum 31 °C. 



Aerobic. 



Distinctive cliaracter : Bluish gran- 

 ules produced in culture. 



Source: Isolated from diseased alfalfa 

 plants. 



Habitat : Vascular pathogen of alfalfa, 

 Medicago sativa. 



Note : Jensen {loc. cit.) regards this 

 species as being almost identical with 

 Corynebacterium helvolum Kisskalt and 

 Berend. He isolated one strain from 

 grass soil which he regards as a sapro- 

 phytic strain of this species. Jensen 

 emphasized the angular arrangement of 

 young cells grown on agar and potato. A 

 faint indication of reduction of nitrates 

 and of diastatic action was obtained. 

 He also reports a weak proteolysis of 

 milk. Optimum reaction is given as pH 

 5.6 to 6.8. A slimy variant of the soil 

 strain was isolated from an old culture in 

 glucose broth which seemed to agree 

 better in its characteristics with the 

 organism as described by Jones and Mc- 

 Culloch than did the non-slimy strains. 



15a. Corynebacterium insidiosum var. 

 saprophyticum Jensen {loc, cit., 42) is 

 based on a non-infectious soil strain. 

 This grew more vigorously w^ith less 

 definite yellow pigment on nutrient agar 

 than the pathogenic strain. Blue-violet, 

 insoluble pigment near edge of growth on 

 glucose agar ; no blue pigment on potato ; 

 no coagulation of milk; higher tempera- 

 ture maximum and more resistance to 

 acid reaction than the pathogenic strains. 

 From grass soil in Australia. 



16. Corynebacterium sepedonicum 

 (Spiekermann and Kotthoff) Skaptason 



and Burkholder. {Bacteritim sepedoni- 

 cum nomen nudum Spiekermann, 111. 

 Landw. Zeitung, S3, 1913, 680; Bacterium 

 sepedonicum Spiekermann and Kotthoff, 

 Landw. Jahr., 46, 1914, 674; Aplanobac- 

 ier sepedonicum. Erw. F. Smith, Intro. 

 Bact. Dis. of Plants, 1920, 207; Phyto- 

 monas sepedonica Magrou, in Hauduroy 

 et al.. Diet. d. Bact. Path., Paris, 1937, 

 411; Skaptason and Burkholder, Phyto- 

 path., 32, 1942, 439.) From Greek 

 sepedonicus, putrefactive. 



Description from Stapp (Ztschr. f. 

 Par., 5, 1930, 756). 



Rods: 0.3 to 0.4 by 0.8 to 1.0 micron. 

 Pleomorphic. Non -motile. Gram-posi- 

 tive. 



Gelatin: Liquefaction slight. 



Agar colonies : Thin, smooth, trans- 

 lucent, glistening, whitish, 2 to 3 mm in 

 diameter. 



Broth: Weak growth. No pellicle. 

 Light sediment. 



Litmus milk: Little change in 6 weeks, 

 after which litmus is reduced. 



Indole not formed. 



No H2S production or feeble. 



Glucose, galactose, fructose, arabinose, 

 xylose, mannitol, glycerol and dulcitol 

 are utilized. 



Starch hydrolysis light. 



Grows in 4 per cent salt . 



Optimum temperature 20° to 23°C. 

 Ma.ximum temperature 31°C. Minimum 

 4°C. 



Distinctive characters : Differs from 

 Corynebacterium michiganense, in that 

 it is white to cream-colored on various 

 media and has a lower optimum tempera- 

 ture. Corynebacterium michiganense 

 does not infect potatoes. 



Source : Stapp used 17 cultures isolated 

 from diseased potatoes. 



Habitat : Causes ring rot of potato 

 tubers in Germany. 



17. Corynebacterium michiganense 

 (Erw. Smith) Jensen. (Bacterium 

 michiganense Erw. Smith, Science, 31, 

 1910, 794; Pseudomonas michiganensis 

 Stevens, The Fungi which Cause Plant 



