Department of Chemistry, University of Patras, Patras, Greece.
Bioresour Technol. 2010 Oct;101(19):7484-91. doi: 10.1016/j.biortech.2010.04.031. Epub 2010 May 18.
A new biocatalyst was prepared by immobilization of Saccharomyces cerevisiae AXAZ-1 yeast cells on whole wheat grains. This biocatalyst was used for 30 repeated batch fermentations of glucose and grape must at various temperatures. The biocatalyst retained its operational stability for a long period and it was proved capable to produce dry wines of fine clarity even at extremely low temperatures (5 degrees C). After the completion of these fermentations the new biocatalyst was used in a scale-up system of 80 L for wine making at ambient (20 degrees C) and extremely low temperatures (2 degrees C). The scale-up process did not affect the fermentative ability of biocatalyst, even at low temperatures, while the produced wines had almost the same improved aromatic profile compare to free cells as revealed by GC and GC-MS analyses. More specifically the results showed that both systems with immobilized cells (laboratory scale and 80 L bioreactor) increased the formation of esters and produced wines with improved aromatic profile compared to those with free cells. Finally an increase in the percentages of total esters and a decrease in those of higher alcohols was observed in lower fermentation temperatures.
通过将酿酒酵母 AXAZ-1 细胞固定在整粒小麦上，制备了一种新型生物催化剂。该生物催化剂用于在不同温度下对葡萄糖和葡萄汁进行 30 次重复分批发酵。该生物催化剂长期保持操作稳定性，并且被证明能够在极低温度（5°C）下生产澄清度极好的干酒。在完成这些发酵后，该新型生物催化剂用于 80L 的葡萄酒酿造放大系统，在环境温度（20°C）和极低温度（2°C）下进行。放大过程并未影响生物催化剂的发酵能力，即使在低温下，而通过 GC 和 GC-MS 分析表明，与游离细胞相比，所生产的葡萄酒几乎具有相同的改善的香气特征。更具体地说，结果表明，固定化细胞（实验室规模和 80L 生物反应器）的两个系统均增加了酯的形成，并产生了具有改善的香气特征的葡萄酒，与游离细胞相比。最后，在较低的发酵温度下，观察到总酯的百分比增加，而高级醇的百分比降低。
