SACCHAROMYCES 



981 



Genus Saccharomyces Meyen, 1838. 



Definition. — No proper thallus. Reproduction by budding and 

 ascospores; fermentation of glucose and saccharose, and often 

 of other carbohydrates. Ascospores with one membrane. No 

 trace of any copulative process. Occasionally rudimentary mycelial 

 tubes present, with transverse septation. 



Remarks. — As already stated, the fungi of this genus, as well as 

 of the genera Cryptococcus, Monilia, Oidium, and Coccidioides, are 

 usually called Blastomycetes, and the diseases induced by them 

 blastomycoses. 



- The fungi of the genera Saccharomyces, Cryptococcus, and Cocci- 

 dioides have a great importance in dermatology, as they give rise 

 to peculiar ulcerative affections of the skin, often resembling a 

 syphilide or a tuberculide. The first cases of blastomycosis were 

 observed in America by Posadas, Wernike, and others, who at first 

 believed them to be a protozoal infection. Later Gilchrist, Ricketts, 

 and others recognized the true nature of the parasites. By some 

 authors (Sanfelice, Roncali, etc.), cancer has been considered to be 

 of blastomycetic origin. 



Fungi of the genus Saccharomyces are very important from an industrial 

 and agricultural standpoint, being the cause of alcoholic fermentation. The 

 best-known yeast is the brewer's yeast, S. cerevisicB, which is slightly ovoid, 

 8 to 9 ^ in diameter. 



Saccharomyces blanchardi Guiart, 1906. 



Found at an operation by Blanchard, Schwartz, and J. Binot, 

 on a patient who had been considered to be suffering from tuber- 

 cular peritonitis. The fungus had produced in the peritoneum 

 a large, whitish, gelatiniform mass, weighing about i kilogramme. 

 The fungus grew well on all sugar media. 



On maltose agar it produced crateriform colonies of a snow-white 

 colour. Presence of asci with eight spores. On gelatine mucoid-like, 

 of greyish colour. Slow liquefaction of the medium. On potato 

 mucoid growth, whitish, darkening after a long time. On carrot 

 growth viscid, abundant; pathogenic to rabbits, in which it 

 induced a general mycosis, terminating fatally. 



Saccharomyces granulatus Vuillemin and Legrain, 1900. 



Observed by Vuillemin and Legrain in a tumour of the sub- 

 maxillary bone. Cells ovoid, 4 to 5 [jL in length, and 3 to 4 in 

 breadth. Cultures pinkish or pinkish-red; ascospores and chlamy- 

 dospores present. Gelatine not liquefied. Sugar reactions not 

 given 



Saccharomyces tumefaciens Curtis, 1896. 



Synonym. — Saccharomyces suhcutaneus tumefaciens Curtis, 1896. 



Found by Curtis in a myxomatous tumour. It appeared in 

 the tissues in the shape of spherical bodies 16 to 20 ^ in diameter, 

 each surrounded by a zone of amorphous substance. Grows well on 

 all sugar media ; in very old cultures asci are seen, with 1-4 spores. 



