FAMILY CORYXEBACTERIACEAE 



395 



19. Corjmebacterium agropyri (O'Gara) 

 comb. nov. (Aplanohacter agropyri 

 O'Gara, Phytopath., 6, 1916, 343; Phijio- 

 monas agropyri Bergey et al., jManual, 1st 

 ed., 1923, 190; Bacterium agropyri Stapp, 

 in Sorauer, Handbuch d. Pflanzenkrank- 

 heiten, 5 Aufl., 2, 1928, 37.) From Greek 

 agros, field and puros, wheat ; M. L. Agro- 

 pyron, wheat grass. 



Rods: 0.4 to 0.6 by 0.6 to 1.1 microns. 

 Capsules. Non -motile. Gram -variable. 



Gelatin : Xo liquefaction. 



Nutrient agar slant : Meager, yellow, 

 very viscid growth. 



Broth : Light clouding with yellow pre- 

 cipitate. 



Milk: Little changed. Yellow sedi- 

 ment formed. 



Nitrites are produced from nitrates. 



Acid but no gas from glucose, lactose, 

 sucrose and glycerol. 



Starch: Hydrolysis feeble. 



Optimmn temperature 25° to 28°C. 



This species is verj^ similar to and may 

 be identical with Corynehacterium rathayi 

 Dowson . 



Source : From slimj'^ heads of wheat 

 grass. 



Habitat : Found on wheat grass, Agro- 

 pyron smithii. 



20. Corynebacteriimi fascians (Til- 

 ford) Dowson. {Phytomonas fascians 

 Tilford, 54th Rept. Ohio Agr. Exp. Sta. 

 Bull. 561, 1936, 39; Jour. Agr. Res., 53, 

 1936, 393; Unnamed pathogen, Lacey, 

 Ann. Appl. Biol., 23, 1936, 308; Dowson, 

 Brit. Myc. Soc. Trans., 25, 1942, 313.) 

 From Latin /ascto, producing a fasciation. 



Rods : 0.5 to 0.9 by 1.5 to 4.0 microns. 

 Non-motile. Gram-positive. 



Gelatin: Xo liquefaction. 



Potato-glucose agar colonies : Light 

 cream-colored colonies appear after 72 

 hours. Punctiform, circular, later cad- 

 mium yellow to deep chrome. 



Nutrient agar slant : After one week 

 streak is filiform, fiat, dull to glistening, 

 smooth, opaque, cream-colored, and 

 butyrous. 



Broth: Slightly turbid. Fragile pel- 

 licle with distinct rim. 



Milk: Litmus becomes blue. Other 

 changes slight. 



Nitrites are produced from nitrates. 



Indole not formed. 



Hydrogen sulfide is produced. 



Acid but no gas from glucose, galactose, 

 fructose, mannose, arabiuose, xylose, mal- 

 tose, sucrose, glycerol, mannitol and dex- 

 trin. No acid from rhamnose, lactose, 

 raffinose and inulin. 



Starch not hydrolj-zed. 



Grows in 8 per cent salt. 



Optimmn temperature 25° to 28°C. 



Aerobic. 



Source : Described from 15 single cell 

 isolates from fasciated growths on sweet 

 peas. 



Habitat : Pathogenic on sweet pea, 

 chrysanthemum, geranium, petunia, to- 

 bacco, etc. 



21. Corynebacterium helvolum (Zim- 

 merman) Kisskalt and Berend. {Bacil- 

 lus helvolus Zimmermann, Bakt. unserer 

 Trink- u. Nutzwiisser, Chemnitz, 1, 1890, 

 52; Bacterium helvolum Lehiiiann and 

 Neumann, Bakt. Diag., 1 Aufl., 2, 1896, 

 254 ; Kisskalt and Berend, Cent, f . Bakt., 

 I Abt., Orig., 81, 1918, 446; Flavobac- 

 terium helvolum Bergey et al., Manual, 1st 

 ed., 1923, 114.) From Latin helvus, of a 

 light bay color. 



Original description supplemented 

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

 Wales, 59, 1934, 37. 



Rods : 0.5 by 1.0 micron, occurring sin- 

 gly. Show angular arrangement due to 

 snapping division. Variable in mor- 

 phology. Non-motile. Gram-positive. 



Gelatin colonies: Small, circular, yel- 

 lowish-gray. Liquefaction. 



Gelatin stab : Slight development along 

 the stab. Napiform liquefaction. 



Agar colonies : Circular, pale yellow, 

 smooth, slightly convex. 



Agar slant : Pale yellow, plumose to 

 spreading, moist, undulate. 



Milk agar : Growth fair to very abun- 



