Institute for Wine Biotechnology, Stellenbosch University, Private Bag X1, Matieland, ZA 7602, South Africa.
Curr Microbiol. 2011 Jun;62(6):1682-8. doi: 10.1007/s00284-011-9914-4. Epub 2011 Mar 16.
Malolactic fermentation (MLF) plays an important role in the production of wine, especially red wines, resulting in microbial stability, deacidification, as well as contributing to the aroma profile. MLF can be influenced by a number of factors. In this study, the influence of pH and ethanol on expression of the structural malolactic enzyme gene (mle) from Lactobacillus plantarum was investigated in a synthetic wine media, as well as in wine using quantitative PCR. Expression of mle was shown to be inducible by the presence of malic acid, with increased expression in the middle of MLF. Expression of mle was also shown to be increased at low pH values and decreased in the presence of ethanol. This indicates the role of MLF in acid tolerance and the negative impact of ethanol on the completion of MLF. The results therefore provide further evidence that L. plantarum should be applied as co-inoculation for MLF where alcohol will initially not have a negative impact on the malic acid degradation.
苹果酸-乳酸发酵（MLF）在葡萄酒生产中起着重要作用，特别是在红葡萄酒中，它可以使微生物稳定、降低酸度，并有助于形成香气特征。MLF 会受到多种因素的影响。在这项研究中，通过定量 PCR 技术，在合成葡萄酒培养基和葡萄酒中，研究了 pH 值和乙醇对植物乳杆菌结构型苹果酸乳酸酶基因（mle）表达的影响。结果表明，mle 的表达受苹果酸的诱导，在 MLF 的中期表达增加。mle 的表达也随着 pH 值的降低而增加，而在乙醇存在的情况下则减少。这表明 MLF 在耐酸方面的作用，以及乙醇对 MLF 完成的负面影响。因此，这些结果进一步证明，在最初不会对苹果酸降解产生负面影响的情况下，应该将植物乳杆菌作为 MLF 的共同接种物进行应用。
