| Abstract: | The free nucleotides of semi-aerobically and aerobically cultured baker's yeast in different industrial stages have been investigated under different conditions: during growth and at rest, and during respiration and fermentation of different substrates. The amounts of protein and nucleic acids diminish progressively during industrial propagation, while the amount of free nucleotides falls only during the last stage of propagation. In yeasts cultured under different conditions of aeration and nutrient addition, the nucleotide spectra were rather similar, but the proportions of the free nucleotides change considerably when the yeast passes from the resting state to growth or metabolism. On transfer from respiration to fermentation the nucleotide spectrum remained practically unchanged. However, a small addition of ethanol to a respiring yeast suspension caused clear alterations in the spectrum, the most obvious being the reduced amount of nucleotides with energy-rich phosphate bonds. |
