酵母ピルベートデカルボキシラーゼによる清酒もろみ中のピルビン酸の減少

概要

論文の詳細を見る
After alcoholic fortification of sake mash, there is a rapid decrease in pyruvic acid and a transient increase in acetaldehyde, which causes an off-flavor in sake. This study was undertaken to gain a better understanding of the changes occurring in these components in sake mash. When cells of a haploid segregant from Saccharomyces cerevisiae ATCC32694 were suspended in 0.05M McIlvaine buffer (pH 6.0) supplemented with 20% (v/v) ethanol and 7mM sodium pyruvate, the overall reduction of viable cells was less than 1% within 1h, and the mol concentration of acetaldehyde progressively increased in parallel with an equivalent decrease of pyruvic acid. Cells treated with 25% ethanol for 1 h exhibited similar activity in the same buffer without ethanol. pH 6 was optimal for the decrease of pyruvic acid as well as pyruvic decarboxylase, and a broad pH activity spectrum was observed. The addition of sorbitol enhanced the decrease in pyruvic acid and increased the concentration of proteins in the buffer. After incubation for 5 d, the supernatant also showed similar activity. Pyruvate decarboxylase activity in the supernatant of the sake mash sharply increased, attaining 4-8 units at pH 7.0 and 20℃ after alcoholic fortification. Acetaldehyde was transported into the viable cells, apparently by the system of facilitated diffusion. When time courses of acetaldehyde in the sake mash were simulated using the constant K_m=6.0mM, V_m=0.23mM/h at a density of 10^8 viable cells/ml, the calculation results showed a good fit to the measured values in all the cases tested.
社団法人日本生物工学会の論文
1995-01-25

酵母ピルベートデカルボキシラーゼによる清酒もろみ中のピルビン酸の減少

スポンサーリンク

概要

著者

関連論文

スポンサーリンク