FAMILY EXTEROBACTERIACEAE 



475 



Agar slant : Growth yellow, glistening. 



Broth : Turbid, with yellow ring. 



Litmus milk: Slow coagulation at 

 37 °C. Slight acidity. Casein slowly 

 dissolved. Litmus reduced. 



Potato : Growth spreading, glistening, 

 yellowish. Medium not discolored. 



Indole formed in peptone solution. 

 Phenol negative. 



Nitrites produced from nitrates. 



No HoS produced. 



No ammonia in broth. 



Feeble acid production without gas 

 from glucose, lactose, sucrose, fructose 

 and glycerol. No growth in closed arm 

 with lactose and glycerol; more or less 

 growth in closed arm with glucose, su- 

 crose, fructose, maltose, raffinose and 

 mannitol. 



Diastase not formed. 



Produces an enzyme capable of dis- 

 solving the middle lamella but without 

 action on cellulose. 



Cohn's solution: Slight turbidity. 



Usehinsky's solution : No growth. 



Fermis' solution with starch jelly : 

 No growth. 



Pigment insoluble in water, alcohol, 

 ether, chloroform or dilute acids. 



Temperature relations : Optimum 30°C. 

 IMinimum 5° to 6°C. Maximum 45°C. 

 Thermal death point 60°C. 



Source : From the mango in Africa. 



Habitat : Causes a disease of the mango 

 (Ma n gife ra indica) . 



19. Erwinia citrimaculans (Doidge) 

 Magrou. (Bacillus citrhnaculaiis Doidge, 

 Ann. Appl. Biol., 3, 1917, 53; Bacterium 

 citrimaculans Burgwitz, Phytopath. Bac- 

 teria, Leningrad, 1935, 154; INIagrou, in 

 Hauduroy et al.. Diet. d. Bact. Path., 

 1937, 203.) From the genus Citrus and 

 Latin 7uaculans, spotting. 



Rods: 0.45 to 0.7 by 0.8 to 3.2 microns. 

 Motile with peritrichous flagella. Con- 

 spicuous capsule present. Gram-posi- 

 tive. Dowson thinks this species Gram- 

 negative (Cent. f. Bakt., II Abt., 100, 

 1939, 184). 



Gelatin : Liquefied. 



Agar colonies: Subcircular, j-ellow, 

 with dense grumose centers. 



Broth: Turbid, with pellicle and sedi- 

 ment. 



]Milk : Coagulated, with precipitation 

 of casein and extrusion of whey. Not 

 peptonized. Litmus gradually reduced. 



Blood serum : Not liquefied. 



Indole is formed. 



Nitrites produced from nitrates with 

 evolution of gas. 



Ammonia produced in broth. 



Acid without visible gas from glucose, 

 sucrose, fructose, galactose, maltose and 

 mannitol. No acid from lactose, glyc- 

 erol, dextrin or starch. 



Diastase not produced. 



Cohn's solution: No growth. 



Usehinsky's solution: Growth present. 



No growth in broth over chloroform. 



Methylene blue and neutral red re- 

 duced. 



Pigment insoluble in water, alcohol, 

 ether, chloroform, carbon bisulfide, dilute 

 acid or alkalis. 



A turbid growth is produced in 10 per 

 cent salt. 



Temperature relations : Optimum 35°C. 

 ^Maximum 43°C. Thermal death point 

 62°C for 10 minutes. 



Facultative anaerobe. 



Source : From diseased lemons and 

 oranges. 



Habitat : Causes a spot disease of 

 citrus. In nature attacks lemons, or- 

 anges, naartjes and has also been success- 

 full}^ inoculated into limes, shaddock, 

 grapefruit and citron. Seville oranges 

 are resistant. 



20. Erwinia rhapontici (^Millard) comb. 

 710V. (Phytomonas rhapontica Millard, 

 Univ. Leeds and Yorkshire Council for 

 Agr. Ed. Bui. 134, 1924, 111; Bacterium 

 rhaponticum Millard, ibid.; Aplanobacter 

 rhaponticum Elliott, Man. Bact. Plant 

 Path., 1930, 12.) From Greek Rha 

 pontic, rhubarb of Pontus, a province 

 of Asia Minor; M. L. Rheum rhaponticum. 



