Studies on yeast growth and sugar consumption in culture medium of final molasses (Department of Agriculiural Chemistry)

(1)pH調整および栄養物添加による予備処理はおこなわないで糖蜜をBalling22°に希釈しただけで, 通気培養により, 396号, M-603-1およびパン酵母の3種の酵母について増殖実験をおこなった。各酵母は200mlの培地宛に一白金耳接種して培養された。(2)M-603-1とパン酵母は接種後24時間で, また396号酵母は接種後28時間で夫々定常曲線を示した。(3)pH値の変化はガラス電極pHメーターにより, 酵母数はトーマ氏ヘマトメーターにより, 夫々測定され, また糖定量はレーン法とベルトラン法を併用しておこなった。(4)各酵母による全糖消費曲線は酵母の増殖とともに減少したが, 直糖消費曲線は不規則であった。(1) Without preliminary treatment such as pH control and nutrient addition, the growth of No. 396,M-603-1,and bread yeast were determined in aeration culture of the diluted final molasses medium with 22°of Balling. Each yeast was separately inoculated to a 200ml culture medium with a platinum loop. (2) The growth curve showed a stationary phase 24 hours after the inoculation with the M-603-1 and bread yeast, and 28 hours after the inoculation with the yeast of No. 396. (3) The change of pH value and number of the yeast were measured with glass electrode pH meter and Thomas Haemocytometer respectively. The sugar consumption by the yeast was also determined according to the methods, of Lane and Bertrand. (4) The consumption of the total sugar by each yeast was indicated by a curve that decreased with the growth of the yeast, whereas that of the reducing sugar was not