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 6ju) 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 ju long and 4-6 jit 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 jit 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. 



