Yeasts have accompanied humans for thousands of years. For most of this time, mankind was unaware of the existence and identity of these industrious microbes. Long after Van Leeuwenhoek´s 17th century drawings of mysterious globules in fermenting beer, the 19th century saw vigorous debates on their functions. Unexpectedly, these debates provided scientists with a fantastic model organism for research. The use of yeast initiated modern biochemistry and the mysterious globules have continued to play a key role in biological research, so much so that the great biophysicist, biochemist, inventor −and Olympic golden medalist− Britton Chance wrote in the late seventies: "If you want to make exploration of physiological and biochemical reactions in a reproducible system, yeast can usually do it better". Our vision of yeast, following the general trend in biological sciences, has again changed dramatically in the last decades with the advent of novel technologies.

Fundamental studies with yeast, on subjects as diverse as cell cycle regulation, membrane assembly or vesicular transport have provided knowledge that is now being applied to issues in human health. Moreover, its use in basic research continues to provide dividends, as shown for example by the recent in vitro reconstruction of the DNA replication process. In 2015, the journal Nature hailed this technical prowess as a major technical feat that would have not been possible "without the considerable genetic and biochemical work of the past 30 years -particularly in budding yeast". The use of yeasts in industry, besides the traditional fermentative processes, continues in the form of cell factories to produce compounds of high added value. So highly appreciated are yeasts that a recent meeting held in September 2016 in Japan was entitled "Yeasts for global happiness".

The present symposium offers a panoramic view of the expanding scope of research with yeasts and, in particular, their ever expanding role as powerful, multi-purpose models systems for cutting-edge research in various domains of the Life Sciences. The generosity of the Fundación Ramón Areces has once again allowed us to gather productive scientists working on different fields of research based on yeasts. Presentations at the symposium span a wide range of topics ranging from basic questions on yeasts biology to practical uses, considering topics as varied as the use of yeasts to engineer new proteins, strategies to adequate their potential to industrial requirements, the utilization of yeasts as models in geroscience and to investigate different humans pathologies such as cancer or protein folding diseases and their value for the production of clinically important compounds.

The study of these different processes reveals strengths and weaknesses of the various approaches used and has provided a drive to obtain a deeper fundamental understanding of the performance of yeast cells in all these applications. The topics treated show clearly that innovation rests on a strong and continuously expanding fundamental knowledge basis that needs time to develop. Claims for immediate translational results, originating from short-sighted administrators, threaten this invaluable foundation for true innovation. Cuts in government spending on basic research, motivated by economic crises and a perceived lack of short-term returns on investment represent a clear danger at a moment in human history where several of the grand challenges faced by our global society require a quantum leap for innovations in the Life Sciences. We hope that the Symposium will attract many interested scientists and we would be glad if it helps to convince decision makers of the enormous value of fundamental research in the yeast field.

Confiamos en que el simposio atraiga a numerosos científicos interesados y nos congratularía si ayudase a convencer a los responsables de la toma de decisiones del gran valor de la investigación básica en el campo de la investigación con levaduras.

The organizers thank Prof. Julio R. Villanueva for his initial stimulus to organize the Symposium and the Fundación Ramón Areces for its generous support and logistic help. They also thank the lecturers who made the Symposium possible with their enthusiastic response.