FAMILY IV. ENTEROBACTERIACEAE 



359 



the middle lamella but without action on 

 cellulose. 



Nitrites produced from nitrates. 



No ammonia in broth. 



Pigment insoluble in water, alcohol, ether, 

 chloroform or dilute acids. 



Temperature relations: Optimum, 30° C. 

 Minimum, between 5° and 6° C. Maximum, 

 45° C. Thermal death point, 60° C. 



Source: Isolated from the mango in 

 Africa. 



Habitat: Causes a disease of the mango 

 (Mangifera indica) . 



17. Erwinia rhapontici (Millard, 1924) 

 Burkholder, 1948. {Phyiomonas rhapontica 

 (sic) Millard, Univ. Leeds and Yorkshire 

 Council for Agr. Ed. Bui. 134, 1924, 111; 

 Envinia rhapontici Burkholder, in Manual, 

 6th ed., 1948, 475; Pectobacterium rhapontici 

 Patel and Kulkarni, Indian Phj'topath., 4, 

 1951, 80.) 



rha.pon'ti.ci. Gr. neut.n. rhaponticum 

 specific epithet of Rheum rhaponticum, rhu- 

 barb; M.L. gen. noun, rhapontici of rhubarb. 



Description taken from Metcalfe (Ann. of 

 Appl. Biol., 27, 1940, 502), where he suggests 

 that this species belongs in Erwinia. 



Rods, 0.5 to 0.8 by 1.2 to 1.5 microns. Mo- 

 tile by means of 3 to 7 peritrichous flagella. 

 Gram-negative. 



Gelatin stab: Beaded growth. No lique- 

 faction. 



Infusion agar: Colonies circular, convex, 



smooth, glistening, translucent, with mar- 

 gins entire, 2 to 3 mm in diameter in 48 

 hours at 25° C. 



Rhubarb agar: Colonies slightly larger, 

 often with a yellowish tinge. 



Tryptophane broth: Turbid with fragile 

 pellicle, a slight rim and slight flocculent 

 deposit. 



Alilk: Acid in 3 to 4 days with or without 

 slight curd separation. No clotting. 



Indole not produced. 



Hydrogen sulfide not produced. 



Cohn's solution: Moderate growth. 



Acid but no gas from arabinose, xjdose, 

 glucose, galactose, fructose, mannose, lac- 

 tose, maltose, sucrose, mannitol, glycerol 

 and salicin. 



Acetylmethylcarbinol produced . 



Growth in citrate solution. 



Starch not hydrolj^zed. 



Nitrites produced from nitrates. 



Chromogenesis: Water-soluble, pinkish 

 pigment in various media. 



Growth from 0° to 37° C. and possibly 

 higher. 



Distinctive characters: Differs from Er- 

 winia aroideae in that it does not liquefy 

 gelatin nor clot milk and is chromogenic. 

 It also has a limited host range. 



Source: Isolated from rotting rhubarb 

 crowns. Metcalfe used 6 strains from various 

 sources in describing this pathogen. 



Habitat: Causes a crown-rot of rhubarb 

 (Rheum rhaponticum) . 



TRIBE III. SERRATIEAE BERGEY, BREED AND MURRAY, 1938. 



(Preprint, Manual, 5th ed., 1938 (October), vi.) 



Ser.ra.ti'e.ae. M.L. gen. noun Serralia type genus of the tribe; -eae ending to denote a 

 tribe; M.L. fem.pl.n. Serratieae the Serratia tribe. 

 Characters as for the genus. 

 There is a single genus. 



Genus VII. Serratia Bizio, 1823, emend. Breed and Breed, 1927* 



(Bizio, Polenta porporina, Biblioteca italiana o sia Giornale de lettera, scienze e arti, 

 30, 1823, 288; Zoagalactina Sette, Memoria storico-naturale sull'arrossimento straordinario 

 di alcune sostanze alimentose osservato nella provincia di Padova I'anno 1819. Venezia, 



* Revised by Prof. Robert S. Breed, New York State Experiment Station, Geneva, New 

 York, November, 1937; further revision by Prof. Robert S. Breed, July, 1955. 



