Evolva SA, Duggingerstrasse 23, 4153 Reinach, Switzerland.
Department of Biology, Technical University Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany.
FEMS Yeast Res. 2018 Jun 1;18(4). doi: 10.1093/femsyr/foy046.
Anthocyanins (ACNs) are plant secondary metabolites responsible for most of the red, purple and blue colors of flowers, fruits and vegetables. They are increasingly used in the food and beverage industry as natural alternative to artificial colorants. Production of these compounds by fermentation of microorganisms would provide an attractive alternative. In this study, Saccharomyces cerevisiae was engineered for de novo production of the three basic anthocyanins, as well as the three main trans-flavan-3-ols. Enzymes from different plant sources were screened and efficient variants found for most steps of the biosynthetic pathway. However, the anthocyanidin synthase was identified as a major obstacle to efficient production. In yeast, this enzyme converts the majority of its natural substrates leucoanthocyanidins into the off-pathway flavonols. Nonetheless, de novo biosynthesis of ACNs was shown for the first time in yeast and for the first time in a single microorganism. It provides a framework for optimizing the activity of anthocyanidin synthase and represents an important step towards sustainable industrial production of these highly relevant molecules in yeast.
花色苷（ACNs）是植物次生代谢物，负责大多数花卉、水果和蔬菜的红色、紫色和蓝色。它们作为人工色素的天然替代品，在食品和饮料行业中的应用越来越广泛。通过微生物发酵生产这些化合物将提供一种有吸引力的替代方法。在这项研究中，我们对酿酒酵母进行了工程改造，以从头开始生产三种基本的花色苷，以及三种主要的反式黄烷-3-醇。筛选了来自不同植物来源的酶，并找到了大多数生物合成途径步骤的有效变体。然而，花色苷合酶被确定为高效生产的主要障碍。在酵母中，这种酶将其大多数天然底物无色花青素转化为非途径类黄酮。尽管如此，花色苷的从头生物合成首次在酵母中得到证实，也是首次在单个微生物中得到证实。它为优化花色苷合酶的活性提供了一个框架，代表着朝着在酵母中可持续工业生产这些高度相关分子迈出了重要一步。
