TORULA. 385 



On the surface of wort-gelatine agar greyish-white colonies 

 form with a slightly hairy appearance. They gradually change 

 to a chocolate-brown colour. On gypsum blocks spore-for- 

 mation is not so abundant as on solid yeast water substrata. 



It ferments maltose, dextrose, Isevulose, and d-galactose, 

 but not /-arabinose, raffinose, lactose, or saccharose ; sacchar- 

 ose is also not inverted. In ordinary beer- wort (about 13-3 

 per cent. Balling) it can produce 7 per cent, by volume of 

 alcohol. 



Optimum temperature for vegetative growth 25 to 28 

 C. ; maximum temperature 38-5 C. ; minimum under 0-5 C. 

 Optimum temperature for spore-formation 25 to 28 C. ; 

 maximum 34-5 to 35 C. ; minimum between 5 and 8 C.* 



II. BUDDING FUNGI WITHOUT SPORE-FORMATION. 



Torula. 



These yeast-like forms were first characterised by Hansen. 

 They are widely distributed, and, therefore, not infrequently 

 occur in physiological analyses connected with fermentation. 

 They occur in both spherical and more or less elongated forms, 

 and are distinguished from the genus Saccharomyces, as first 

 pointed out by Hansen, by their inability to form endogenous 

 spores. In most cases they multiply only by budding, in some 

 few cases also by the formation of mycelium. 



According to the author's researches, certain Torula forms 

 may act as disease-yeast, for they multiply freely and give rise 

 to a kind of turbidity in weakly fermented, high-fermentation 

 beers, when these are bottled ; the character of this turbidity, 

 however, is somewhat different from that caused in low- 

 fermentation beer by the wild Saccharomycetes. 



In sugar-works, the writer finds Torula forms occurring 

 extensively, frequently in large quantities, even in the finished 



* Certain dubious species of Saccharomycetes must be mentioned, one 

 isolated by Metschnikoff, Monospora cuspidata, occurring as a parasite in 

 Daphnia, which has long cells and contains needle-shaped spores, and another, 

 Nematospora Coryli, isolated by Peglion from hazel nuts, containing eight spores 

 to a cell, in two bundles, each of four spores. The spores carry a long flagellum 

 at each end, which disappears before the germination of the spore takes place. 



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