Serra Audrey, Strehaiano Pierre, Taillandier Patricia
Laboratoire de Génie Chimique, UMR CNRS 5503, INP-ENSIACET, 5 Rue Paulin Talabot, BP 1301, 31106 Toulouse Cedex 1, France.
Int J Food Microbiol. 2005 Oct 25;104(3):257-65. doi: 10.1016/j.ijfoodmicro.2005.03.006. Epub 2005 Jun 23.
The species Saccharomyces bayanus var. uvarum possesses interesting enological characteristics but produces high concentration of volatile fermentative compounds not desirable in Sauvignon blanc wines. Interspecific hybrids between Saccharomyces cerevisiae and S. bayanus var. uvarum were made in order to join the main parental advantages. Two hybrids were selected on the basis of their fermentation characteristics and their karyotypes, i.e. they have a different mitochondrial DNA. In order to produce these hybrids as active dry yeast to be used as starter in wine-making, their optimal environmental conditions for growth, i.e. temperature and pH, were determined as the objective of our work. Using a two-level factorial design it was found that the two parental strains have different optimal temperature but for the two strains, pH does not have a significant influence on growth. The influence of temperature on biomass productivity for hybrid strains were strictly identical, so we suppose that the main genes coding for temperature sensitivity were not contained in mitochondrial DNA, but in nuclear DNA. Moreover the reactions of hybrid strains to the temperature variations were similar to the one of S. bayanus var. uvarum. This latter strain could have a majority of genes responsible of temperature sensitivity dominant in comparison with those of the strain S. cerevisiae.
巴氏酵母变种葡萄汁酵母具有有趣的酿酒特性，但会产生高浓度的挥发性发酵化合物，这在长相思葡萄酒中是不理想的。酿酒酵母和巴氏酵母变种葡萄汁酵母之间的种间杂交是为了结合主要亲本的优势。基于它们的发酵特性和核型选择了两个杂交种，即它们具有不同的线粒体DNA。为了将这些杂交种生产成活性干酵母用作酿酒的起始菌株，我们工作的目标是确定它们生长的最佳环境条件，即温度和pH值。使用二级析因设计发现，两个亲本菌株具有不同的最佳温度，但对于这两个菌株，pH值对生长没有显著影响。温度对杂交菌株生物量生产力的影响完全相同，所以我们推测编码温度敏感性的主要基因不在线粒体DNA中，而在核DNA中。此外，杂交菌株对温度变化的反应与巴氏酵母变种葡萄汁酵母相似。与酿酒酵母相比，后一种菌株可能具有大多数负责温度敏感性的显性基因。
