A global ecological and biogeographic map of Saccharomyces to learn how and where species were formed

SAMPAIO, JP; ALMEIDA, P; GONCALVES, C; LIBKIND, DIEGO; GONCALVES, P

Madison

Congreso; 13th International Congress on Yeasts; 2012

ICY

The study of the natural biology of Saccharomyces has been hampered by two related factors. First, the key role that several species of this genus play in man-driven fermentations confounded the search and detection of the truly natural ecological niches where the different species evolved for the last 20 million years. Secondly, the difficulty in isolating strains from substrates other than grape must and related man-made environments restricted the development of studies focused on the natural history of these yeasts. An example that illustrates this state of affairs is that the vineyard, a man-made environment, is viewed by most as the natural habitat of S. cerevisiae. However, recent work is gradually changing this situation and the number of reports describing the isolation of Saccharomyces species from natural habitats is increasing. We have found a worldwide association of Saccharomyces with trees of the order Fagales in temperate ecosystems in the Northern and Southern hemispheres. Basal Saccharomyces lineages found in such natural systems are S. uvarum and S. eubayanus, the former having a wider distribution. Other lineages like S. arboricolus, S. kudriavzevii and S. mikatae appear to have relatively restricted geographic distributions, contrary to the most derived species, S. paradoxus and S. cerevisiae, which have a global distribution. A phylogeographic and ecological model of the genus Saccharomyces will be discussed taking into consideration recent results concerning species distribution, intra-specific genetic diversity, population structure and inter-species phenotypic discontinuities.