266 FAMILY OF SACCHAROMYCETACEAE 



It ferments lactose giving 0.108 per cent of alcohol in eight days. 

 Grotenfelt pretends to have obtained ascospores on potato but the 

 existence of these ascospores does not seem to be well established. 

 Then, again, it is possible that this species may be a Torula. 



SACCHAROMYCES LACTIS a. Dombrowski l 



This species, isolated from Bulgarian yoghourt, has been described 

 in the laboratory of Professor Jensen at Copenhagen by Dombrowski. 

 Generally it is a yeast with elliptical cells but it may present cells 

 elongated to 18 JJL especially on solid media. On grape must, the cells 

 may be 9.0-6.0 /* long and 3.75-3.25-3.00 ju wide. In cultures on the 

 cover glass the formation of giant colonies is easily observed. 



Sporulation is difficult to obtain especially after successive cultur- 

 ing in liquid media. Ascospores are formed at the end of about 44 hours 

 at 25 C. in cells arising from solid media. The ascospores are round 

 and to the number of three to four in each asc. They germinate by 

 ordinary budding. 



On beer must gelatin in plates, the colonies are lenticular. In 

 stabs, the growth is along the line of inoculation as one approaches 

 the surface. Giant colonies on beer must gelatin, after two months, 

 offer a delicate structure with concentric zones and rays running out 

 from the center. 



Saccharomyces lactis a acts like a bottom yeast in sugar solutions. 

 It never produces a scum, but a ring is formed at the end of six weeks 

 at room temperature. In beer must, it produces a fermentation ac- 

 companied by the formation of an agreeable odor. It decolorizes 

 the wort in 10 days and yields after 4J months four to five grams of 

 alcohol per 100 c.c. It causes an active fermentation in milk at 23- 

 25 C. It ferments lactose, saccharose and dextrose but does not act 

 on maltose. A small amount of acids are found among the products 

 of the fermentation. 



SACCHAROMYCES LACTIS ft. Dombrowski 1 



This species has been isolated by Dombrowski from a sample of 

 milk fermented at 45 C. The cells possess variable forms. One may 

 find egg-shaped or elliptical cells aside from the elongated cells which 

 may reach 20 microns. These latter cells remain attached and form 

 long chains or a sort of mycelium. On beer wort, the cells measure 

 7.6-5.5-4.6-3.8 JLC in length and 4.6-3.8 ju in width. Sporulation is ac- 



1 Dombrowski, W. Die Hefen in Milch und Milchprodukten. Cent. Bakt. 

 28, 1909. 



