Thursday, May 24, 2007

Saccharomyces cerevisiae genetic diversity

As one would expect, this is research by a French group.

Bread, beer and wine: Saccharomyces cerevisiae diversity reflects human history


Molecular Ecology May 2007

Fermented beverages and foods have played a significant role in most societies worldwide for millennia. To better understand how the yeast species Saccharomyces cerevisiae, the main fermenting agent, evolved along this historical and expansion process, we analysed the genetic diversity among 651 strains from 56 different geographical origins, worldwide. Their genotyping at 12 microsatellite loci revealed 575 distinct genotypes organized in subgroups of yeast types, i.e. bread, beer, wine, sake. Some of these groups presented unexpected relatedness: Bread strains displayed a combination of alleles intermediate between beer and wine strains, and strains used for rice wine and sake were most closely related to beer and bread strains. However, up to 28% of genetic diversity between these technological groups was associated with geographical differences which suggests local domestications. Focusing on wine yeasts, a group of Lebanese strains were basal in an FST tree, suggesting a Mesopotamia-based origin of most wine strains. In Europe, migration of wine strains occurred through the Danube Valley, and around the Mediterranean Sea. An approximate Bayesian computation approach suggested a postglacial divergence (most probable period 10 000–12 000 bp). As our results suggest intimate association between man and wine yeast across centuries, we hypothesize that yeast followed man and vine migrations as a commensal member of grapevine flora.

No comments:

Locations of visitors to this page