Cordente Antonio G, Heinrich Anthony, Pretorius Isak S, Swiegers Jan H
The Australian Wine Research Institute, Glen Osmond, Adelaide, SA, Australia.
FEMS Yeast Res. 2009 May;9(3):446-59. doi: 10.1111/j.1567-1364.2009.00489.x. Epub 2009 Feb 19.
The production of hydrogen sulfide (H(2)S) during fermentation is a common and significant problem in the global wine industry as it imparts undesirable off-flavors at low concentrations. The yeast Saccharomyces cerevisiae plays a crucial role in the production of volatile sulfur compounds in wine. In this respect, H(2)S is a necessary intermediate in the assimilation of sulfur by yeast through the sulfate reduction sequence with the key enzyme being sulfite reductase. In this study, we used a classical mutagenesis method to develop and isolate a series of strains, derived from a commercial diploid wine yeast (PDM), which showed a drastic reduction in H(2)S production in both synthetic and grape juice fermentations. Specific mutations in the MET10 and MET5 genes, which encode the catalytic alpha- and beta-subunits of the sulfite reductase enzyme, respectively, were identified in six of the isolated strains. Fermentations with these strains indicated that, in comparison with the parent strain, H(2)S production was reduced by 50-99%, depending on the strain. Further analysis of the wines made with the selected strains indicated that basic chemical parameters were similar to the parent strain except for total sulfite production, which was much higher in some of the mutant strains.
在发酵过程中产生硫化氢（H₂S）是全球葡萄酒行业中一个常见且重要的问题，因为低浓度的硫化氢会赋予葡萄酒不良的异味。酿酒酵母在葡萄酒中挥发性硫化合物的产生过程中起着关键作用。在这方面，H₂S是酵母通过硫酸盐还原序列同化硫的必要中间产物，关键酶是亚硫酸盐还原酶。在本研究中，我们使用经典诱变方法开发并分离了一系列菌株，这些菌株源自一种商业二倍体葡萄酒酵母（PDM），在合成发酵和葡萄汁发酵中，它们的H₂S产量都大幅降低。在六个分离菌株中鉴定出了MET10和MET5基因的特定突变，这两个基因分别编码亚硫酸盐还原酶的催化α亚基和β亚基。用这些菌株进行的发酵表明，与亲本菌株相比，H₂S产量降低了50%至99%，具体取决于菌株。对用选定菌株酿造的葡萄酒的进一步分析表明，除了总亚硫酸盐产量外，基本化学参数与亲本菌株相似，某些突变菌株的总亚硫酸盐产量要高得多。
