Dekkera bruxellensis-spoilage yeast with biotechnological potential, and a model for yeast evolution, physiology and competitiveness

Dekkera bruxellensis is a non-conventional yeast normally considered a spoilage organism in wine (off-flavours) and in the bioethanol industry. But it also has potential as production yeast. The species diverged from Saccharomyces cerevisiae 200 mya, before the whole genome duplication. However, it displays similar characteristics such as being Crabtree-and petite positive, and the ability to grow anaerobically. Partial increases in ploidy and promoter rewiring may have enabled evolution of the fermentative lifestyle in D. bruxellensis. On the other hand, it has genes typical for respiratory yeasts, such as for complex I or the alternative oxidase AOX1. Dekkera bruxellensis grows more slowly than S. cerevisiae, but produces similar or greater amounts of ethanol, and very low amounts of glycerol. Glycerol production represents a loss of energy but also functions as a redox sink for NADH formed during synthesis of amino acids and other compounds. Accordingly, anaerobic growth required addition of certain amino acids. In spite of its slow growth, D. bruxellensis outcompeted S. cerevisiae in glucose-limited cultures, indicating a more efficient energy metabolism and/or higher affinity for glucose. This review tries to summarize the latest discoveries about evolution, physiology and metabolism, and biotechnological potential of D. bruxellensis.