Using RFLP-mtDNA for the rapid monitoring of the dominant inoculated yeast strain in industrial wine fermentations.

The analysis of restriction fragment length polymorphism of mitochondrial DNA (mtDNA-RFLP) has been applied as a test to monitor the abundance of the starter yeast strain during industrial wine fermentations without previous isolation of yeast colonies. For white wine fermentations, we performed a rapid assay consisting in taking a sample of fermenting must, purifying the DNA from harvested cells, and obtaining the restriction patterns by digestion with the endonuclease HinfI. The same protocol, but adding an overnight cultivation step before DNA purification, was also applied to red wine fermentations.