Philippine Science Letters
vol. 6 | no. 1 | 2013
published online March 22, 2013


ARTICLE


Delta typing and analysis of alcohol tolerance genes (erg2, hsp104, sod2) in six local wine strains of Saccharomyces cerevisiae


by Cynthia T. Hedreyda* and Zahara Joy A. Guiamal

National Institute of Molecular Biology and Biotechnology, College of Science, University of the Philippines, Diliman, Quezon City, Philippines 1101




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The availability of reliable procedures to check if desirable wine strains of Saccharomyces cerevisiae are maintained is valuable for wine producers to ensure the quantity and quality of wines produced. Random Amplification of Polymorphic DNA (RAPD) in a previous study, generated Polymerase Chain Reaction (PCR) profiles that could distinguish S. cerevisiae wine strains (that exhibited growth in 10% and 15% ethanol) from a non-wine strain (that exhibited growth inhibition in 10 and 15% ethanol) and wine strains from one another. In this study, delta (δ) typing and sequence analysis of three specific genes (erg2, hsp104 and sod2) implicated in alcohol tolerance were performed in search of a faster and cheaper procedure to distinguish strains of S. cerevisiae. The use of delta primer pair, δ12 / δ2, resulted in a distinct profile for each of yeast strains studied. Compared to RAPD, which makes use of several random primers and several PCR runs, delta typing involves one PCR run and uses a single δ primer pair. Sequence analysis of three S. cerevisiae genes that code for proteins involved in major mechanisms proposed for alcohol tolerance of the species, revealed single (for the erg2 and hsp104 genes) to multiple (for the sod2 gene) nucleotide variations. The nucleotide polymorphisms observed for the erg2 and sod2 genes are not expected to result in amino acid variation while the polymorphisms found in the amplified fragments of the hsp104 gene resulted in amino acid variation at position 236. Nucleotide and protein polymorphisms in these genes, however, could not discriminate the yeast strains studied and the variation did not correlate with the reported strain differences in alcohol tolerance. Results of this study suggest that delta (δ) typing with primers δ12 and δ2, is more discriminatory, faster, and less expensive than RAPD and is recommended to be the first procedure to perform in trying to discriminate wine strains of S. cerevisiae. Polymorphisms observed in the three genes, erg2, hsp104 and sod2, cannot be used as a basis for designing PCR primers that could generate discriminating profiles of wine strains versus the non-wine strain of yeast used. Sequence analysis of several other genes implicated in alcohol tolerance is recommended in order to identify a gene or a group of genes with nucleotide and amino acid sequence variation that could distinguish wine strains of S. cerevisiae


*Corresponding author
Email Address: chedreyda@mbb.upd.edu.ph
Submitted:August 12, 2012
Revised: February 3, 2013
Accepted:February 4, 2013
Published: March 22, 2013
Editor-in-charge: Eduardo A. Padlan
Reviewers:
Sevilla D. Detera-Wadleigh
Windell L. Rivera