314 NON-SACCHAROMYCETES OR DOUBTFUL YEASTS 



D. COLORED TORULA 



Among the colored Torula, the red yeasts are the most numerous. 1 

 They are especially numerous in dust of the air. Some form myco- 

 dermic scums and may be classed as Mycoderma. 



TORULA PULCHERRIMA. Lindner 



Lindner 2 has found this Torula 



Fig. 142. Torula pulcherrima. Old Cells 

 and Their Germination (after Lindner) . 



membrane ruptures itself and an 

 yeast ferments dextrose, d-mannose 



on numerous occasions, especially 

 on various fruits and also on the 

 excrement of potato bugs. Red 

 pigments are formed. 3 In beer 

 wort, its cells are at first ellipti- 

 cal but later they become larger 

 and round with a large fat glob- 

 ule in their interior. They possess 

 a thick membrane (Fig. 142). 

 During germination the external 

 active budding takes place. This 

 and levulose. 



TORULA MUCILAGINOSA. Jorgensen 4 



The cells are oval (5 to 5.6 ju long and 2^t wide). Inoculated into 

 beer wort, this yeast at first produces a slight cloudiness and at the 

 same time a ring of a mucous yeast with a rose color as well as a 

 mucous sediment visible only after shaking the culture. The ring 

 continues to extend on the walls of the vessel which soon finds itself 

 covered from top to bottom with a rose-colored growth. There seems 

 to be no vegetation as a sediment. Clumps of this mucous ring may 

 fall to the bottom of the flask. The surface colonies on gelatin with 



1 per cent wort are round, faintly rose colored, moist, shiny and a 

 little convex. The young colonies have a united border. The old 

 ones are hollowed in the middle and provided with little transverse 



1 Beijerinck has described a Saccharomyces pulcherrimus which secretes a 

 colorless chromogen which becomes a deep red in the presence of iron salts. He 

 even suggests that this variety may be used as a test for iron. (Beijerinck, M. W. 

 Chromogenic yeasts a new biologic reaction for iron. Arch, neerland. physiol. 



2 (1918), 609-15. Chem. Absts. 13 (1919), 1082. 



2 Lindner, P. Ueber rot und Schwartz gefarbte Sprosspilze. Wochenschr. 

 f. Brau. 4, 1887. 



3 All of the red yeasts have been grouped by bacteriologists into a special 

 group known as "red yeasts." 



4 Jorgensen, A. Die Mikroorganismen der Garungsindustrie. Berlin. 5th 

 edition. Paul Parey. 1909. 



