476 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Description from Metcalfe, Ann. of 

 Appl. Biol., ^7, 1940, 502, where he sug- 

 gests it belongs in Erivinia. 



Rods: 0.5 to 0.8 by 1.2 to 1.5 microns. 

 Motile with 3 to 7 peritrichous flagella. 

 Gram-negative. 



Gelatin stab : Beaded growth. No 

 liquefaction. 



Infusion agar: Colonies circular, con- 

 vex, smooth, glistening, translucent, 

 with margins entire, 2 to 3 mm in diam- 

 eter in 48 hours at 25°C. 



Rhubarb agar : Colonies slightly larger, 

 often with a yellowish tinge. 



Tryptophane broth : Turbid with frag- 

 ile pellicle, a slight rim and slight floccu- 

 lent deposit. 



Milk : Acid in 3 to 4 days with or with- 

 out slight curd separation. No clotting. 



Indole not produced. 



Nitrites formed from nitrates. 



Acetylmethylcarbinol produced. 



No hydrogen sulfide produced. 



Cohn's solution : Moderate growth. 



Acid but no gas from arabinose, xylose, 

 glucose, galactose, fructose, mannose, 

 lactose, maltose, sucrose, mannitol, glyc- 

 erol and salicin. 



Growth in citrate solution. 



Starch not hydrolyzed. 



Chromogenesis : Water-soluble pinkish 

 pigment in various media. 



Growth from 0°C to 37 °C and possibly 

 higher. 



Distinctive characters : Differs from 

 Erwinia aroideae in that it does not 

 liquify gelatin nor clot milk and is chro- 

 mogenic . It also has a limited host range . 



Source : From rotting rhubarb crowns. 

 Metcalfe used 6 isolates from various 

 sources in describing the pathogen. 



Habitat : Causes a crown-rot of rhu- 

 barb. 



21. Erwinia lathyri (Manns and Tau- 

 benhaus) Holland. {Bacillus lathyri 

 Manns and Taubenhaus, Gardener's 

 Chronicle, 53, 1913, 215; Manns, Dela- 

 ware Agr. Exp. Sta., Bui. 108, 1915, 23; 

 Holland, Jour. Bact., 5, 1920, 218; Bac- 



terium lathyri Burgwitz, Phytopath. 

 Bacteria, Leningrad, 1935, 76.) From 

 the genus LatMjrus. 



Rods : After 24 hours at 25° to 28°C, 

 0.6 to 0.85 by 0.75 to 1.5 microns, with 

 rounded ends. No capsules. Motile 

 with peritrichous flagella. Gram-nega- 

 tive. 



Gelatin colonies: After 8 days, cir- 

 cular, slightly convex, edges smooth. 

 Liquefaction too slow to show on plate. 



Gelatin stab: Growth best at surface. 

 Line of stab filiform. Liquefaction slow, 

 fairly well begun in four weeks, complete 

 in three months. 



Agar colonies: After 24 hours, yellow, 

 stellate to amoeboid, smooth, glistening, 

 slightly raised, entire. Centers gran- 

 ular, yellow. 



Agar slant: Growth filiform, slightly 

 convex, smooth, glistening, opaque, buty- 

 rous, light to deep yellow. Odor absent. 



Broth: Strong turbidity in 24 hours, 

 little or no pellicle. Sediment scant. 



Litmus milk: Slow increase of acidity, 

 not always sufficient to cause coagulation. 

 Digestion of casein slow and variable. 



Potato : Growth rapid, filiform, slightly 

 convex, smooth, glistening, butyrous to 

 slightly viscid. Light to deep yellow. 

 Medium not discolored. 



Indole is formed. 



Cohn's solution: No growth. 



Uschinsky's solution: Rapid growth, 

 sometimes a pellicle. Fluid viscid. 



Asparagine solution : Good growth. 



Nitrites are not produced from ni- 

 trates. 



Ammonia produced in broth and as- 

 paragine solution. 



No gas from carbohydrates. Acid 

 from glucose, lactose, sucrose, mannitol 

 and glycerol. No growth in closed arm. 



Diastase not formed or extremely 

 weak. 



Growth in broth over chloroform 

 absent. 



Growth inhibited by 4 per cent NaCl. 



Temperature relations : Optimum 28° 



