14.] 



ETHYL ALCOHOL 



47 



the two first are fermented by sedi- 

 mentary yeast (Fischer and E. F. Arm- 

 strong, Ber. 35, 3144). 



The various species of Saccharomyces 

 behave differently towards different 

 sugars, their behaviour having relation- 

 ship to the enzymes contained in the 

 yeast cell : 



S. cerevisite, S. pastorianus, and 8. el- 

 lipsoideus ferment saccharose, maltose, 

 and the products of their inversion, 

 i. e. dextrose and laevulose, but not lac- 

 tose; S. ilicis and S. aquifolii ferment 

 saccharose, maltose, and dextrose ; S. 

 pyriformis and S. vordermanni ferment 

 saccharose ; S. exiguus, S. marxianus, 

 and S. jorgensenii ferment saccharose 

 and dextrose, but not maltose; S. lud- 

 wigii ferments dextrose and saccharose, 

 but neither maltose nor lactose ; S. pombe 

 ferments dextrose and saccharose ; 

 S. acidi laclici and S. fragilis ferment 

 lactose (summarised from Jorgensen's 

 ' Mikroorganismen, &c.' chap. v). 

 S. membranafaciens is inactive towards 

 most sugars (Fischer and Thierfelder, 

 Ber. 27, 2031). So also is S. hansenii. 

 S. hyalosporus, S.farinosus, and S. ano- 

 malus, var. belgicus (all Lindner's), can- 

 not ferment maltose, dextrose, or sac- 

 charose (' Die Garungsorganismen, &c.,' 

 Klocker, p. 203). a, ludwigii is inca- 

 pable of fermenting galactose, and may 

 therefore be used for separating this 

 sugar from dextrose (Thomas, Comp. 

 Rend. 134, 610). 8. apiculatus fer- 

 ments dextrose and mannose (Cremer, 

 Zeit. Biol. 29, 525), but not saccharose, 

 lactose, maltose, or galactose (Voit, Zeit. 

 Biol. 29, 149 ; Hansen and Amthor, 

 Zeit. physiol. Ch. 12, 563). 



S. ( = Sckizosaccharomi/ces) octosporus 

 ferments dextrose and maltose, but not 

 saccharose (Beyerinck, Centr. Bakter. 

 12, 49 ; Fischer and Lindner, Ber. 28, 

 984 ; 3034). S. productivus, S. mem- 

 branfpfaciens, and S. pombe are incapable 

 of fermenting d-galactose under ordinary 

 conditions, but this sugar is ferment- 

 able under suitable conditions by S. 

 cerevisia, by 8. pastorianus I, II, III, by 

 S. ellipsoideus I, II, by S. marxianus, 

 and (slowly) by the mould Manilla can- 

 dida (Bau, Bied. Centr. 26, 213). The 

 yeasts appear to be capable of gradual 



adaptation or ' acclimatisation ' towards 

 this sugar (Dubourg, Comp. Rend. 128, 

 440; Dienert, Ibid. 569; 617; Ann. 

 Inst. Past. 14, 139 : S. ludwigii does 

 not seem to be amenable to this treat- 

 ment : for adaptation of yeasts to 

 saccharose see also Dubourg, loc. cit. : 

 for variation in chemical activity of 

 yeasts produced by cultivation see Han- 

 sen, Zeit. ges. Brau. 25, 41 ; 57 ; 70 ; 

 82 ; Journ. Fed. Inst. 7, 299). 



8. anomalus, vars. I, II, III, and IV, has 

 been investigated by Steuber (Zeit. ges. 

 Brau. 23, 3; 17; 33; Journ. Fed. 

 Inst. 6, 123). I ferments saccharose, 

 glucose, and fructose, but not maltose, 

 lactose, or galactose ; II ferments sac- 

 charose slowly, but not fructose, glucose, 

 maltose, lactose, or galactose ; III and 

 IV produce a trace of alcohol from 

 fructose, but do not ferment any of the 

 other sugars. 



According to Barker (Ann. Bot. 

 1900, 215) S. anomalus of Hansen 

 can ferment glucose, fructose, and 

 saccharose, but not maltose. This 

 yeast also produces ethyl and amyl 

 acetates. S. bailii of Lindner can fer- 

 ment dextrose and ( invert ' sugar ; S. 

 mail duclauxl of Kayser (found in cider) 

 can ferment invert sugar, but neither 

 maltose nor saccharose (' Die Garungs- 

 organismen, &c./ Klocker, p. 215). Sac- 

 charomyces opuntice, which ferments the 

 must of Indian figs, can ferment dex- 

 trose and laevulose, but not lactose, 

 raffinose, galactose, mannitol, or dulcitol 

 (Ulpiani and Sarcoli, Gazz. 31, 395). 

 From a mixture of S. pastorianus II 

 and S. opuntice sodium fluoride elimi- 

 nates the latter (Ibid. Atti Real. Accad. 



[5] 11, 173). 



Milk sugar is fermentable by three 

 yeasts from Armenian f mazun/ by 

 Weigmann's yeast, Sachsia suaveolens, 

 and, possibly, by Manilla variabilis 

 (Lindner, Ch. Centr. 1901, 1, 56 ; 

 Woch. Brau. 17, 713). The top fermen- 

 tation yeast, S. pastoriamts arborescens, 

 can ferment dextrose and laevulose, 

 but not galactose nor di- and trisac- 

 charides (Van Laer, Bull. Assoc. Belg. 

 16, 177 ; Journ. Fed. Inst. 8, 763). 



S. (Schizosaccharomyces) pombe and 

 octosporus and S. logos are said to be 



