NATURALLY OCURRING YEASTS AND LACTIC ACID BACTERIA FROM NOVA SCOTIA VINEYARDS
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abstract -conference
Plain language summary
Yeasts and lactic acid bacteria (LAB) on grapes are influenced by regional climatic conditions. Wine quality is strongly impacted by the yeast and LAB involved in the fermentative process. The objective of this study was to isolate, identify and characterize naturally occurring yeasts and LAB in Nova Scotia vineyards to improve wine quality.
Grapes from the cultivars L’Acadie, Riesling, New York Muscat, and Pinot Noir grown at multiple vineyard sites in the Annapolis Valley of Nova Scotia were collected to isolate yeast and LAB strains. Using commercial kits we extracted total genomic DNA from yeast and LAB cells followed by accurate identification based on DNA sequence analysis. We identified 13 yeast species including Hanseniaspora uvarum, Saccharomyces cerevisiae, Aureobasidium pullulans and Rhodotorula glutinis. The LAB isolates were phylogenetically grouped into five putative genotypes belonging to Lactococcus lactis, Lactobacillus animalis, Pediococcus pentosaceus, Enterococcus mundtii and Enterococcus faecium. Identified yeast strains were characterized with respect to sulphur dioxide and ethanol resistance, β-glucosidase activity and hydrogen sulphide production. Based on the results, we have selected the most promising yeast strains to be used for wine fermentation. The research results will help create a national yeast and malolactic fermentation (MLF) bacteria bank and database, which will be accessible to grape growers and provide more options for wine makers to define their products in local and international markets.
Abstract
Yeasts and lactic acid bacteria (LAB) on grapes are influenced by regional climatic conditions. Wine quality is strongly impacted by the yeast and LAB involved in the fermentative process. The objective of this study was to isolate, identify and characterize naturally occurring yeasts and LAB in Nova Scotia vineyards to improve wine quality.
Grapes from the cultivars L’Acadie, Riesling, New York Muscat, and Pinot Noir grown at multiple vineyard sites in the Annapolis Valley of Nova Scotia were collected to isolate yeast and LAB strains. Using commercial kits we extracted total genomic DNA from yeast and LAB cells followed by accurate identification based on DNA sequence analysis. We identified 13 yeast species including Hanseniaspora uvarum, Saccharomyces cerevisiae, Aureobasidium pullulans and Rhodotorula glutinis. The LAB isolates were phylogenetically grouped into five putative genotypes belonging to Lactococcus lactis, Lactobacillus animalis, Pediococcus pentosaceus, Enterococcus mundtii and Enterococcus faecium. Identified yeast strains were characterized with respect to sulphur dioxide and ethanol resistance, β-glucosidase activity and hydrogen sulphide production. Based on the results, we have selected the most promising yeast strains to be used for wine fermentation. The research results will help create a national yeast and malolactic fermentation (MLF) bacteria bank and database, which will be accessible to grape growers and provide more options for wine makers to define their products in local and international markets.