SACCHAROMYCES COREANUS 255 



This yeast has been isolated from the manufacture of sugar in 

 Saxony. 1 It is composed of short ellipsoidal or spherical cells in 

 which the diameter may reach from 3 to 6 /i, exceptionally 8 /u (Fig. 

 120). When the species is cultivated in a solution of dextrose with 

 5 to 8% ammonium sulphate added, it produces walled cells. The 

 maximum temperature for budding in must is 33-34 C., the optimum 

 is 28-29 C. Sporulation is easily accomplished as well on liquid media 

 as on solid media. The maximum temperature for the formation of 

 ascs is about 32 and 29 C. Ascospores commence to appear at this 

 temperature at the end of 21 hours. The ascospores are spherical 

 and measure from 1.5 to 3 fji in diameter. Their number is ordinarily 

 two per asc, but it may vary from one to four. The vegetative cells 

 are able to resist a temperature of 130 dry heat for a half hour, and 

 from 66-67 moist heat. According to Owen this yeast is able to 

 resist 90 C. for 10 minutes which would locate the thermal death point 

 at 90. 



SACCHAROMYCES COREANUS. Saito 



This species was isolated by Saito 2 from Koji from Korea. The 

 cells are spherical, oval or sausage shaped, and possess a very re- 

 sistant wall. Their average dimension is from 3-7 p. The contents 

 are homogeneous and hyaline, sometimes 

 with large vacuoles. The cells dissociate 

 rapidly in such a way that they often appear 

 isolated. 



This yeast forms ascospores very easily 

 on plaster blocks. The temperature limits 

 for sporulation are: minimum 1820; op- 

 timum 31-34; and maximum toward 35- 

 36 C. Vegetation from Sediment; 



Each asc possesses from one to four 



ascospores, most of them having two to four (2 to 3.5 /z in diameter). 

 The ascospores germinate by ordinary budding. 



S. coreanus produces a moist scum in sugar solutions at 25. It 

 ferments dextrose, levulose, saccharose, d-galactose, melibiose and 

 raffinose, but has no action on maltose, lactose, arabinose, inuline 

 or dextrin. 



Giant colonies develop on decoction of Koji gelatin and have a 



1 Artari, A. Ueber einen im Safte d. Zuckerfabriken in Gemeinschaft mit 

 Leuconostoc schadlich auftretenden, den Zucker zu Alkohol u. Saure vergarendeu 

 Saccharomyces (S. zopfii). Abh. d. naturf. ges. zu Halle, v. XXI, 1897. 



2 Saito, K. Notizen iiber einige Koreanische Garungsorganismen. Centr. f. 

 Bak., v. XXVI, 1910. 



