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MANUAL OF DETERMINATIVE BACTERIOLOGY 



Genus IV. Butyribacteritun Barker and Haas.* 



(Jour. Bact., 47, 1944, 301.) From the chemical term, butyric and M. L. bacterium, 

 a small rod. 



Non-motile, anaerobic to microaerophilic, straight or slightly bent rods. Gram- 

 positive. Ferment carbohydrates and lactic acid forming acetic and butyric acids, 

 and carbon dioxide. Generally catalase negative but sometimes weakly positive. 

 Intestinal parasites. 



The type species is Butyrihacterhim rettgeri Barker and Haas. 



. 1. Butyribacterium rettgeri Barker and 

 Haas. (Strain 32, Lewis and Rettger, 

 Jour. Bact., 40, 1940, 298; Barker and 

 Haas, Jour. Bact., 47, 1944, 303.) Named 

 for L. F. Rettger, The American bac- 

 teriologist. 



Rods : Straight or slightly bent, non- 

 capsulated. 0.7 by 2.3 microns. Occur 

 singly, in pairs and short chains. No 

 branched cells observed but some cells 

 have swollen club-shaped ends. Non- 

 motile. Gram-positive. 



Glucose-cysteine agar : Colonies cir- 

 cular, entire or finely irregular margin, 

 translucent, often with opaque center, 

 grayish-white with yellowish tinge, con- 

 vex when small, later umbonate, glisten- 

 ing, smooth, finely granular. Develop 

 slowly attaining a diameter of 1 .5 mm in 

 7 days. 



Try ptone -yeast extract-lactate agar : 

 Colonies similar to above except larger 

 (2 mm in 4 days at 37°C). Pulvinate 

 rather than umbonate in cross sections. 



Glucose-cysteine-broth : Abundant tur- 

 bidity and sediment. No pellicle. 



Agar stab (King and Rettger's medium. 

 Jour. Bact., 44, 1942, 302) : Heavy growth 

 in 2 days. Gas production often causes 

 slight splitting of agar. 



Acetic and butyric acid and CO2 pro- 



duced from glucose and maltose. Occa- 

 sionally a small amount of visible gas is 

 produced. Lactic acid fermented read- 

 ily without visible gas. Arabinose, 

 xylose, lactose, sucrose, trehalose, rham- 

 nose, mannitol, sorbitol, dulcitol and 

 glycerol are not fermented. 



Not proteolytic. 



Indole and hydrogen sulfide not formed. 



Temperature relations : Optimum 37°C. 

 Maximum 40 to 45°C. Minimum 15°C. 



Generally catalase negative. 



Anaerobic. 



Source : From intestinal contents of a 

 white rat. 



Habitat : Presumably found generally 

 in the intestine of mammals. 



NoTKs: Pederson (Jour. Bact., 50, 1945, 

 478) has found that cultures of two 

 species described by Eggerth (Jour. 

 Bact., 30, 1935, 289 and 290) produce 

 higher fatty (presumably butyric) acids 

 and lactic acid from glucose. These are 

 named Bacteroides avidus and B. limosus 

 by Eggerth. Probably these species 

 belong in the genus Butyribacterium. 



Bacillus cadaveris butyricus Buday 

 (Cent, f , Bakt., I Abt., 24, 1898, 374) may 

 also belong in this genus. 



♦Prepared by Prof. C. S. Pederson, New York State Experiment Station, 

 Geneva, New York, January, 1945; reviewed by Dr. H. A. Barker, Berkeley, 

 California. 



