FAMILY BACTERL\CEAE 



601 



tral or alkaline A stratum of blood-red 

 serum is seen above the precipitated 

 casein and above this a yellowish-white 

 layer of cream. An intensive sweet 

 odor that becomes disagreeable. 



Potato: Growth rapid, spreading, 

 grayish, later yellow. On incubation a 

 deep golden yellow color develops after 

 6 to 8 days. A darkening of the medium 

 occurs around the culture, but soon dis- 

 appears ; later the whole potato becomes 

 a weak yellowish -red. 



Indole not formed (Fuller and John- 

 son, loc. cit.). Indole formed (Chester, 

 Manual Determ. Bact., 1901, 174). 



Blood serum: Liquefied (Fuller and 

 Johnson, loc. cit.). Not liquefied (Heff- 

 eran, Cent. f. Bakt., II Abt., 11, 1903, 

 456). 



Nitrites produced from nitrates. 



No gas from carbohydrates. 



Slight H;S production (Matzuschita, 

 loc. cit.). 



Red pigment insoluble in water, alco- 

 hol, ether, chloroform, and benzol. 

 Soluble (Hefferan, loc. cit., 529) . Yellow 

 pigment insoluble. 



Distinctive character: Milk becomes 

 blood-red in 12 to 20 days. 



Non-pathogenic for mice (Fuller and 

 Johnson, loc. cit.). 



Optimum temperature 28'' to 35°C. 



Aerobic (Fuller and Johnson, loc. cit.). 

 Facultative anaerobe CHefferan, loc. 

 czi., 530). 



Source: Isolated from red milk bj- 

 Hueppe in Wiesbaden in 1886. Isolated 

 from feces of a child by Baginsky (Cent, 

 f. Bakt., 6, 1889, 137). Isolated from 

 Ohio River water by Fuller and Johnson 

 (loc. cit.). Isolated from Mississippi 

 River water bj' Hefferan (Joe. cit.). 

 Tataroff isolated a rose fluorescent coc- 

 cobacterium {Bacillus rosafluorescens 

 Kruse, in Fliigge, Die Mikroorganismen, 

 3 Aufl., ^, 1896, 305; Bacterium rosa 

 jluorescens Chester, Ann. Rept. Del. 

 Col. Agr. Exp. Sta., 9, 1897, 142) which 

 Migula reports as identical, but which 

 Hefferan considers atypical. 



Habitat : Probably widely distributed 

 in nature. 



2. Bacterium subrufum Burri and 

 Staub. (Burri and Staub, Landwirtsch. 

 Jahrb. d. Schweiz, Jfi, 1926, 1006; Ser- 

 ratia subrufa Bergey et al.. Manual, 3rd 

 ed., 1930, 123.) From Latin sub, some- 

 what and riifus, red. 



This organism is stated to be closelj^ 

 related to or possibly identical with 

 Bacterium eryihrogenes. 



3. Bacterium linens Weigmann. (Or- 

 ganismus IX, Wolff", Milchwirt. Zent., 

 5, 1909, 145; Weigmann, in Wolff, Cent. 

 f. Bakt., II Abt., 28, 1910, 422, and in 

 Weigmann, ^Mykologie der Milch, 62, 

 1911,220.) From Latin, daubing, smear- 

 ing, or spreading over. 



Also see Steinfatt, Milchwirt. 

 Forsch., 9, 1930, 7; Kelly, Jour. Dairy 

 Sci., 20, 1937, 239; Albert, Long and 

 Hammer, Iowa Agr. Exp. Sta. Res. Bui. 

 328, 1944. 



Rods: Average 0.62 bj' 2.5 microns 

 when grown 1 to 2 days on trj^ptone glu- 

 cose extract agar. Non -motile (Wolff). 

 Gram-positive (Kelly, loc. cit.). 



Gelatin colonies: At 18°C punctiform 

 at first; after 12 days about 1 mm in 

 diameter, compact, circular, shiny, 

 brownish-j-ellow to red-brown. Lique- 

 faction. 



Gelatin stab: At 21°C crateriform 

 liquefaction, becoming infundibuliform 

 on extended incubation. Rate of lique- 

 faction varies considerably with differ- 

 ent cultures, some completing it in 15 

 daj's, others not completing it even on 

 long incubation. 



Agar colonies: On tryptone glucose 

 extract agar at 21 °C after 1 to 2 days, 

 colonies convex, glistening, entire and 

 cream-colored, becoming brown on ex- 

 tended incubation; diameters 2 to 5 mm. 

 On special cheese agar with incubation 

 in oxygen, luxuriant growth, the color 

 becoming bright orange to reddish- 

 brown in 4 or 5 days. 



