Intracellular biosynthesis of melatonin and other indolic compounds in Saccharomyces and non-Saccharomyces wine yeasts

Certain bioactive compounds that derive from tryptophan have been determined in fermented foods, which suggests that the role of yeast is putative in origin. Melatonin is a neurohormone in humans that plays an important role in health. The activity of other compounds, such as 3-indoleacetic acid, has been recently highlighted, and interest in elucidating the conditions of their production has grown. However, the biosynthesis of melatonin by yeasts remains unclear to a large extent. Therefore, this work was undertaken to demonstrate the unequivocal synthesis of melatonin and other compounds that derive from tryptophan metabolism by yeast by determining them in the intracellular compartment. By high-resolution mass spectrometry and a validated method, tryptophan itself, melatonin, serotonin, N-acetyl-5-hydroxytryptamine and 3-indoleacetic acid, were identified in the intracellular compartment of Saccharomyces and non-Saccharomyces wine yeasts.