222 



FAMILY OF SACCHAROMYCETACEAE 



During germination the ascospores swell up and the warts on their 

 surfaces disappear. Germination is accomplished by ordinary bud- 

 ding. (Fig. 40.) In wort cultures no scum is formed but often a 

 rudimentary ring may be observed. Giant colonies on gelatin, at 

 the end of a month, have a grayish white color resembling wax. The 

 border is almost entire; the center is slightly raised and of a white 

 color. This species ferments dextrose and levulose actively, raffinose 

 moderately and inuline with difficulty. It has no action on maltose 

 or lactose. It inverts saccharose rapidly and ferments it. In wort 

 at 25 C. D. globosus produces a rather rapid fermentation. After 

 five days, it forms 1.25 per cent of alcohol by volume, and after 8 

 days 1.30 per cent. 



DEBAROMYCES TYROCOLA. Konokotin 



This yeast was isolated from Dutch 

 cheese prepared in Russia. It is a 

 yeast in which the copulation tends to 

 become heterogamic. The copulation 

 may be either iso- or heterogamic but 

 the latter seems to be most frequent. 

 It is accomplished as in the preced- 

 ing species. The ascs usually contain 

 a single ascospore which germinates 

 by budding. This species ferments 

 Fig. 91-A. Debaromyces tyrocola dextrose, levulose, galactose, saccha- 

 (after Konokotin). rose an( J l ac tose. 



Genus IV. Nadsonia 



Ascs preceded by a heterogamic copulation between a mother cell 

 (macrogamete) and a bud from it (microgamete). The macrogam- 

 ete forms a bud which changes into an asc provided with one asco- 

 spore having a verrucose wall. 



NADSONIA FULVESCENS. Sydon 

 Syn. GUILLIERMONDIA FULVESCENS (Nadson and Konokotin) 1 



This yeast was found along with Endomyces magnusii. It bears 

 some resemblance to Debaromyces globosus but differs from it in its 

 sporulation and Nadson and Konokotin have created a new genus for it. 



It is a yeast with oval cells, elliptical or shaped like a lemon. 



1 Nadson, G. A. and Konokotin, A. G. Guilliermondia, eine neue Hefengattung 

 mit heterogamer Kopulation. Cent. Bakt. 34 (1912) 241-242. 



