Multilocus sequence typing of oenological Saccharomyces cerevisiae strains

This study describes the application of a multilocus sequence typing (MLST) analysis for molecular discrimination at the strain level of Spanish wine yeast strains. The discrimination power of MLST is compared to mitochondrial RFLP analysis. Fragments of the ADP1, ACC1, RPN2, GLN4, and ALA1 genes were amplified by PCR from chromosomal DNA of 18 wine Saccharomyces cerevisiae strains. Ten polymorphic sites were found in the five loci analyzed showing 13 different genotypes, with 11 of them represented by only one strain. RFLP analysis of the same 18 wine yeast strains showed seventeen different mitochondrial patterns. Phylogenetic relationships among the strains analyzed, inferred by MLST data, showed wine isolates of S. cerevisiae as a rather homogeneous group. The discrimination potential of mitochondrial RFLP analysis was superior to the MLST scheme used in this work. However, MLST analysis allowed an easy construction of reliable phylogenetic trees. MLST analysis offers the possibility of typing wine S. cerevisiae strains simultaneously to the study of the genetic relationship among them.