Maestre Oscar, García-Martínez Teresa, Peinado Rafael A, Mauricio Juan C
Departamento de Microbiología, Universidad de Córdoba, Edificio Severo Ochoa, Campus Universitario de Rabanales, 14014 Córdoba, Spain.
Appl Environ Microbiol. 2008 Feb;74(3):702-7. doi: 10.1128/AEM.01805-07. Epub 2007 Dec 7.
The effect of overexpression of the gene ADH2 on metabolic and biological activity in Saccharomyces bayanus V5 during alcoholic fermentation has been evaluated. This gene is known to encode alcohol dehydrogenase II (ADH II). During the biological aging of sherry wines, where yeasts have to grow on ethanol owing to the absence of glucose, this isoenzyme plays a prominent role by converting the ethanol into acetaldehyde and producing NADH in the process. Overexpression of the gene ADH2 during alcoholic fermentation has no effect on the proteomic profile or the net production of some metabolites associated with glycolysis and alcoholic fermentation such as ethanol, acetaldehyde, and glycerol. However, it affects indirectly glucose and ammonium uptakes, cell growth, and intracellular redox potential, which lead to an altered metabolome. The increased contents in acetoin, acetic acid, and L-proline present in the fermentation medium under these conditions can be ascribed to detoxification by removal of excess acetaldehyde and the need to restore and maintain the intracellular redox potential balance.
已经评估了基因ADH2过表达对巴氏酵母V5在酒精发酵过程中的代谢和生物学活性的影响。已知该基因编码乙醇脱氢酶II（ADH II）。在雪莉酒的生物陈酿过程中，由于没有葡萄糖，酵母必须在乙醇上生长，这种同工酶通过将乙醇转化为乙醛并在此过程中产生NADH发挥重要作用。在酒精发酵过程中基因ADH2的过表达对蛋白质组图谱或与糖酵解和酒精发酵相关的一些代谢物（如乙醇、乙醛和甘油）的净产量没有影响。然而，它间接影响葡萄糖和铵的摄取、细胞生长以及细胞内氧化还原电位，从而导致代谢组发生改变。在这些条件下发酵培养基中乙偶姻、乙酸和L-脯氨酸含量的增加可归因于通过去除过量乙醛进行的解毒以及恢复和维持细胞内氧化还原电位平衡的需要。
