Cape Peninsula University of Technology, PO Box 1906, Bellville, 7535, South Africa.
Int J Food Microbiol. 2013 May 15;163(2-3):80-8. doi: 10.1016/j.ijfoodmicro.2013.02.011. Epub 2013 Mar 1.
Forty-three South African Torulaspora delbrueckii yeast isolates from the ARC Infruitec-Nietvoorbij yeast culture collection, the T. delbrueckii type strain (CBS 1146), one reference T. delbrueckii strain (CBS 4663), two T. delbrueckii strains isolated from commercial yeast blends (Viniflora® Harmony.nsac and Viniflora® Melody.nsac), and a commercial Saccharomyces cerevisiae yeast (VIN 13) had their identities confirmed and were characterised using conventional and molecular microbiological techniques. These included a selection of growth media as well as CHEF electrophoretic karyotyping and PCR-RFLP analyses. Based on the biochemical and physiological results the strains were divided into 13 groups. The performances of the yeasts were also monitored by means of laboratory-scale fermentations in grape must at 15 °C and 22 °C. The fermentation kinetic data showed that at 22 °C, the yeasts were divided into two distinct groups, a faster and a slower fermenting group. The fermentation curves of the laboratory-scale study at 15 °C showed that, at this lower temperature, the yeasts also fermented at different speeds, but the fermentation curves showed greater separation. The biochemical and physiological grouping did not coincide with the fermentation abilities and good fermenters could be found in more than one group. Chemical analyses of the resultant wines (alcohol, volatile acidity, glycerol, total SO2, residual sugar) were used in Principle Component Analyses. The yeasts that grouped close to the S. cerevisiae reference strain (VIN 13) showed more acceptable wine chemical profiles, while those further away displayed less acceptable profiles. Three locally isolated strains and one commercial T. delbrueckii yeast strain, Viniflora® Harmony.nsac. produced wines with acceptable chemical profiles at both temperatures. These strains also had comparable fermentation kinetics to the S. cerevisiae reference. Therefore, depending on the fermentation temperature, different T. delbrueckii strains will be suitable for specific wine styles and some may even be considered for single inoculations without S. cerevisiae in industrial fermentations.
从 ARC Infruitec-Nietvoorbij 酵母培养物收藏中，43 株南非 Torulaspora delbrueckii 酵母分离株、一株 T. delbrueckii 标准菌株（CBS 1146）、一株参考 T. delbrueckii 菌株（CBS 4663）、两株从商业酵母混合物中分离出的 T. delbrueckii 菌株（Viniflora® Harmony.nsac 和 Viniflora® Melody.nsac）和一株商业酿酒酵母（VIN 13）被确认身份，并使用常规和分子微生物学技术进行了特征描述。这些技术包括选择生长培养基以及 CHEF 电泳核型分析和 PCR-RFLP 分析。根据生化和生理结果，将这些菌株分为 13 组。还通过在 15°C 和 22°C 的葡萄汁中进行实验室规模发酵来监测酵母的性能。发酵动力学数据表明，在 22°C 下，酵母分为两个截然不同的群体，一个发酵速度较快，一个发酵速度较慢。在 15°C 的实验室规模研究的发酵曲线表明，在较低温度下，酵母的发酵速度也不同，但发酵曲线的分离程度更大。生化和生理分组与发酵能力不一致，在一个以上的组中可以找到良好的发酵剂。使用主成分分析对所得葡萄酒的化学分析（酒精、挥发酸、甘油、总 SO2、残留糖）进行分析。与酿酒酵母参考菌株（VIN 13）接近的酵母分组显示出更可接受的葡萄酒化学特征，而距离较远的酵母显示出不太可接受的特征。三种本地分离株和一种商业 T. delbrueckii 酵母株 Viniflora® Harmony.nsac 在两种温度下都能生产出具有可接受化学特征的葡萄酒。这些菌株的发酵动力学与酿酒酵母参考菌株相当。因此，根据发酵温度，不同的 T. delbrueckii 菌株将适合特定的葡萄酒风格，有些甚至可以考虑在工业发酵中不使用酿酒酵母进行单一接种。
