302 YEASTS AND YEAST-LIKE FUNGI 



Rhodotorula. The family Rhodotorulaceae consists of asporog- 

 enous yeasts, non-fermentive and possessing carotinoid pigments, 

 both of which characters are found in Sporobolomyces as well. There 

 is only one genus,®' ^* Rhodotorula, strains of which have been given 

 a variety of specific names as glutinis, mucilaginosa, rubra, sanguinea, 

 which serve to indicate the most striking characters of the group, 

 namely, a sticky or mucoid growth and a red color. All species 

 except one which is yellow are some shade of red or orange. A study 

 of the chemistry of the pigments in one species has been made by 

 Fromageot and Tchang.*' Species have been created on the basis of 

 morphological A'ariations of the cells, i.e., their tendency to form oval 

 or elliptical cells or to produce pseudomycelium; upon differences in 

 consistency of the growth; upon variations in the shade of color 

 produced, and sometimes apparently for no reason at all! The rea- 

 son for considering Rhodotorulae as degenerated Basidiomycetes is 

 that they are so very like Sporobolomycetaceae. Cultures of Sporo- 

 bolomyces lost their ability to form the typical forcibly discharged 

 spores and were then indistinguishable from Rhodotorula. And other 

 cultures of Rhodotorula suddenly acquired the faculty of producing 

 these basidiospores and became "Sporobolomyces." Both the Sporo- 

 bolomycetaceae and the Rhodotorulaceae are distinguished from all 

 other yeast-like organisms in their production of carotinoid pig- 

 ments, and from many other yeasts in their total lack of any fermen- 

 tive activity. 



Lodder recognizes thirteen species and ten varieties of Rhodo- 

 torula and Harrison and Ciferri and Radaelli have recognized more. 

 These twenty-three taxonomic entities were obtained by Lodder from 

 thirty-seven strains labeled to represent thirty-five species and one 

 variety sent to her from various culture collections. If so few strains 

 represent so many species, the chances are that only a fraction of 

 the species are described and most strains which one isolates are 

 likely to be unnamed species or varieties. Although there is possibly 

 good taxonomic justification for the recognition of these species and 

 varieties, little is gained in identifying species of Rhodotorula except 

 by the specialist. If only one species is recognized it is Rhodotorula 

 glutinis. See Figs. 113 and 114. 



Rhodotorulae are common air contaminants, not known to be of. 

 much economic importance. They do not occur frequently in soil, 

 and their natural habitat is unknown. A serious discoloration of 

 sauerkraut has been reported as due to these yeasts. They are fre- 

 quently isolated from dairy products. Conditions of high acidity, 

 low nitrogen content, and high salt content, which keep down bac- 



