208 FAMILY OF SACCHAROMYCETACEAE 



by their necks. (Fig. 85.) The number of ascospores varies in each 

 asc. They are spherical (2.7 to 6.3 JJL in diameter) and are relatively 

 resistant. Germination is accomplished by budding. Guillieraiond 

 has noticed frequently cases of parthenogenesis in this yeast in which 

 the ascs form without preliminary copulation. On decoction of " Koji," 

 -o cJ ^ n * s y eas ^ P r duce3 a white farinaceous scum. 

 On the surface of this scum a number of bub- 

 bles of carbon dioxide form. The scum increases 

 oO <9 <> XT slowly and turns to a light brown. 



8 The giant colonies are raised,, dry and light 

 5 gray in color. The surface is concentrically 

 Fig. 85. Copulation and ringed and cut up by fissures. The edge of the 



Formation of the Ascs colony is notched. Under the colony numerous 

 in Zyg. Japonicus. , , , , ,. , ,. , 



bubbles of gas may be found. 



The cultures on gelatin have a light brown appearance. This 

 species ferments dextrose, levulose and maltose but has no action on 

 6-galactose, lactose, saccharose, melibiose, raffinose, a-methyl-gluco- 

 side and inuline. Zyg. japonicus by the character of its scum, ap- 

 proaches the genera Willia and Pichia very much. It is distinguished, 

 however, by the fact that the scum completely developes only in 

 decoctions of "Koji." Takahashi and Yukawa 1 have recently re- 

 described this yeast as follows: 



This species was isolated from many samples. Since this yeast 

 and Zygosaccharomyces salsus develop and form particular grayish 

 brown films even on a " Shoju " which any other kinds of film-form- 

 ing yeast could not grow, both these yeasts are feared in storing 

 " Shoju." Moreover, this species very easily forms large numbers 

 of sporulated cells. 



Young cells from the surface cultures on " Koji "-extract agar 

 are round (commonly 4-8 c.c.) or oval, and contain glycogen. In 

 old cultures club-shaped or mycelial cells are often observed. Most 

 of the cells in a diluted "Shoju" are elongated abnormally and in- 

 crease the number of vacuoles. 



On plate culture of wort gelatin, this yeast forms a grayish white, 

 crater-like, elevated colony with smooth periphery, and the color 

 turns brownish after the lapse of time. On "Koji "-extract-gela- 

 tin streak culture, the growth shows a grayish white, somewhat 

 dried, lustered, folded covering with fine toothed edge. On " Koji "- 

 extract culture at 23 C. it forms mealy white, small filmy fragments 

 on the surface, and covers the whole surface after 3 days. The film 



1 Takahashi, and Yukawa, M. On the budding fungi of "Shoju-Moromi." 

 Original Communications of the 8th Infernational Congress of Applied Chemistry, 

 14 (1912), 155-171. 



