Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, ICEB II, Departamento de Farmácia, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro. CEP 35, Ouro Preto, MG, 400-000, Brazil.
Antonie Van Leeuwenhoek. 2012 Feb;101(2):379-92. doi: 10.1007/s10482-011-9643-5. Epub 2011 Sep 20.
In this work, we have used classical genetics techniques to find improved starter strains to produce cachaça with superior sensorial quality. Our strategy included the selection of yeast strains resistant to 5,5',5″-trifluor-D: ,L: -leucine (TLF) and cerulenin, since these strains produce higher levels of higher alcohols and esters than parental strains. However, no clear relationship was observed when levels of flavoring compounds were compared with the levels expression of the genes (BAT1, BAT2, ATF2, EEB1 genes) involved with the biosynthesis of flavoring compounds. Furthermore, we determined the stability of phenotypes considered as the best indicators of the quality of the cachaça for a parental strain and its segregants. By applying the principal component analysis, a cluster of segregants, showing a high number of characteristics similar to the parental strain, was recognized. One segregant, that was resistant to TLF and cerulenin, also showed growth stability after six consecutive replications on plates containing high concentrations of sugar and ethanol. "Cachaça" produced at laboratory scale using a parental strain and this segregant showed a higher level of flavoring compounds. Both strains predominated in an open fermentative process through seven cycles, as was shown by mitochondrial restriction fragment length polymorphisms analysis. Based on the physical chemical composition of the obtained products, the results demonstrate the usefulness of the developed strategies for the selection of yeast strains to be used as starters in "cachaça" production.
在这项工作中，我们使用了经典遗传学技术来寻找改良的起始菌株，以生产具有更高感官品质的甘蔗酒。我们的策略包括选择对 5,5',5″-三氟-D:,L: -亮氨酸 (TLF) 和 Cerulenin 具有抗性的酵母菌株，因为这些菌株比亲本菌株产生更高水平的高级醇和酯。然而，当比较风味化合物的水平与参与风味化合物生物合成的基因（BAT1、BAT2、ATF2、EEB1 基因）的表达水平时，没有观察到明显的关系。此外，我们确定了被认为是甘蔗酒质量最佳指标的表型稳定性，用于亲本菌株及其分离株。通过应用主成分分析，我们识别出了一组分离株，这些分离株表现出与亲本菌株高度相似的特征。一个对 TLF 和 Cerulenin 具有抗性的分离株，在含有高浓度糖和乙醇的平板上连续复制六次后，也表现出生长稳定性。使用亲本菌株和该分离株在实验室规模生产的“甘蔗酒”显示出更高水平的风味化合物。这两种菌株在七个循环的开放式发酵过程中占主导地位，这可以通过线粒体限制性片段长度多态性分析得到证明。基于获得产物的物理化学组成，结果表明所开发的策略在选择酵母菌株作为“甘蔗酒”生产中的起始菌株方面非常有用。
