342 NON-SACCHAROMYCETES OR DOUBTFUL YEASTS 



downward into the agar at points along the streak. There is a rapid 

 villous development in gelatin stab cultures. A heavy pellicle is 

 formed in sugar mediums and beer wort. Giant colonies are very 

 distinctive. 



"Physiologic Characters. No sugars are fermented; there is no 

 change in litmus milk. 



"This mycoderma is not distinguishable from several other species, 

 for example, M. cerevisiae, as far as the morphologic and physiologic 

 characters enumerated are concerned. An examination of photographs 

 of the giant colonies of various Mycoderma species revealed the fact 

 that none of these species produce the peculiar rugose-pitted type 

 formed by the foregoing species. The production of such type of 

 growth is not confined to giant colonies on glucose agar, but is present 

 on slants of glucose and beer wort agar." 



MYCODERMA TANNICA. Asai 



Asai l has isolated a new yeast which causes dark brown or black 

 spots on leather. The yeast grows in dextrose or levulose or other 

 sugar solutions with an ammonium salt or amino acid as the source 

 of nitrogen. It does not grow readily in dilute tannin solution but 

 when dextrose and amino acids are added good growth takes place. 

 Small amounts of alcohol and carbon dioxide are formed. 



MYCODERMA ACIDIPANI. Rossi 2 



The cells are oval in shape (3.2-6.6 X 2.3-3 M) and are united 

 in branching groups. There are 1 or 2 refractive granules in each 

 cell. On must gelatin, the cells are white, round, and provided with 

 a slightly filamentous border. In grape must, or wine, the delicate 

 scum is at first compact, later thick and adherent to the walls. If 

 agitated, it falls to the bottom of the container. There is no fermen- 

 tation in must, but a notable diminution in the content of alcohol 

 and a marked increase in acidity. This yeast normally develops at 

 a concentration of from 9 to 10 per cent of alcohol and withstands 

 from 1 to 2 per cent of tartaric acid. The temperature limits are 2-5 C. 

 and 32 C. The optimum is between 22 C. and 27 C. Wine con- 

 taining this yeast may be sterilized by heating for 10 hours at 45 C. 

 and 1 hour at 50 C. or by an exposure of one hour to direct sunlight. 



1 Asai, T. Physiological investigation of a new yeast which flourishes in 

 tanning liquors. Jour. College Science Imperial University, Tokyo, 39, 1-42. 

 Journal of the Chemical Society, January, 1919. 



1 Rossi, G. Micoderma del vino. Le Stazioni Sperimentali Agrarie Italiene. 

 50, 1917. 



