SAITO'S MYCODERMA 335 



MYCODERMA DECOLORANS. Will 1 



This yeast possesses cylindrical cells sometimes a little conical 

 with a median constriction more or less marked. The dimensions 

 are variable. The temperature limits for growth are 5 and 42 C. 

 The optimum is 25-31 C. This species oxidizes alcohol very ener- 

 getically. The giant colonies on must gelatin are very flat, thin and 

 quite spread out. The edge is often lobate. The center is a little 

 concave with the peripheral portion lined with concentric bands. This 

 species causes a disease in beer characterized by a decoloration of the 

 substrate, an odor and a musty taste. 



SAITO'S MYCODERMA 



Saito 2 has described four species of yeasts as Mycoderma. One 

 isolated from "Shiro-koji " forms a dry scum folded, white and thick. 

 The young cells are oval (4 to 6/1) with abundant protoplasm, with 

 one or more vacuoles and one or three fat globules. This yeast causes 

 no fermentation. 



The other two have been encountered in "Chinese yeast " from 

 Corea along with Saccharomyces Coreanus. On sugar solutions, one 

 forms a dry, thin, dull scum. The cells are ellipsoidal, often shaped 

 like a sausage (4-8 IJL long and 4-6 /x, wide) with homogeneous con- 

 tents and provided with small granules. It produces only a slow 

 liquefaction of gelatin and a very feeble fermentation. The other, 

 on the surface of sugar solutions, forms a farinaceous, white scum. 

 The cells are oval or spherical (2-6 (JL in diameter) and possess an in- 

 terior with one or more fat globules. On gelatin streaks, the growth 

 is snow white and presents a rough surface. Liquefaction is quite 

 rapid. This species produces a feeble fermentation. 



The fourth species was isolated from fermentation products of the 

 soy bean. It has irregularly shaped cells, elongated or oval, much 

 like those of Saccharomyces pastorianus, with a large vacuole contain- 

 ing refractive granules. On gelatin plates, this yeast produces small 

 colonies with a moist appearance and with a slightly raised center. 

 The edge is provided with fine indentations. It does not liquefy gela- 

 tin. On streak cultures, a grayish white deposit is produced and a 

 finely indented border without liquefaction of the medium. The 

 giant colony has a white appearance, the surface being much folded 

 and irregular. 



1 Will, H. See reference under Mycoderma valida. 



2 Saito, K. Mikrobiol. Studien iiber die Soya-Bereitung. Cent. Bakt. 17, 

 1906; Notes on Formosan Fermentation Organisms. The Botanical Magazine, 

 15, 1902; Preliminary Notes on Some Fermentation Organisms of Corea. The 

 Botanical Magazine, Tokyo, 23, 1909. 



