FAMILY ENTEROBACTERIACEAE 479 



TRIBE III. SERRATEAE BERGEY, BREED AND MURRAY. 



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



Small, aerobic rods, usually producing a bright red or pink pigment on agar and 

 gelatin. There is a single genus. 



Genus I . Serratia Bizio emend. Breed and Breed* 



(Bizio, Biblioteca italiana o sia Giornale de lettera, scienze e arti, 30, 1823, 288; 

 Zaogalactina Sette, Sull'arrossimento straordinario di alcune sostanze alimentose 

 osservato nella provincia di Padova I'anno 1819. Venezia, 1824, 51 ; Coccobacterium 

 Schmidt and Weis, Die Bakterien, 1902, 10; Erythrobacillus Fortineau, Compt. rend. 

 Soc. Biol., Paris, 58, 1905, 104; Dicrobactrum Enderlein, Sitzber. Gesell. Naturf. 

 Freunde, Berlin, 1917, 309; Breed and Breed, Cent. f. Bakt., II Abt., 71, 1927, 435.) 

 Named for Serafino Serrati, the Italian physicist who invented a steam boat at Florence 

 before 1787. 



Small, aerobic, rapidly liquefying, nitrate reducing, Gram-negative, peritrichous 

 rods which produce characteristic red pigments. White to rose-red strains that lack 

 brilliant colors are common. Coagulate and digest milk. Liquefy blood serum. 

 Typical species produce CO2 and frequently H2 from glucose and other sugars; also 

 acetic, formic, succinic and lactic acids, acetylmethylcarbinol and 2,3 butylene glycol. 

 Saprophytic on decaying plant or even animal materials. 



The type species is Serratia mnrcescens Bizio. 



Key to the species of genus Serratia. 



I. Pigment not especially water-soluble, readily soluble in alcohol. 



A. No visible gas from glucose. 



1. Inconspicuous pellicle, if any, on plain gelatin. 



1. Serratia marcescens. 



2. Brilliant orange-red pellicle on plain gelatin. 



2. Serratia indica. 



B. Produce enough H2 with the CO2 from glucose to show gas in fermentation 



tubes. 



1. Acetylmethylcarbinol produced. 



3. Serratia plymuthicum. 



2. Acetylmethylcarbinol not produced. 



4. Serratia kilensis. 

 II. Pigment soluble in water and alcohol. 



5. Serratia piscatorum. 



1. Serratia marcescens Bizio. (Po- Sette, Memoria storico-naturale sulP 



lenta porporina, Biblioteca italiana, 30, arrossimento straordinario di alcune 



1823,288.) From Latin, dissolving into a sostanze alimentose. Venezia, 8°, 1824, 



fluid or viscous matter. 51 ; Protococcus imetrophus Meneghini, 



Synonyms: Zoagalactina imetrofa 1838, see Trevisan, Rend. R. Inst. Lomb. 



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

 New York, Nov., 1937; further revision by Prof. Robert S. Breed, Nov., 1945. 



