The elaboration of sparkling wine is a demanding process requiring technical as well as scientific skills. Uncovering the role of the terroir to the final product quality is of great importance for the wine market.
Although the impact of the yeast strains and their metabolites on the final product quality is well documented, the action of bacteria still remains unknown. The malolactic fermentation (MLF) is carried out by the lactic acid bacteria after the alcoholic fermentation in order to ensure the microbial stability during the second fermentation that takes place in the bottle or in tanks. Oenococcus oeni is the only selected species to drive MLF that has been commercialized for sparkling wine elaboration and it is naturally present on grapes, in the cellar and also in the final product. However, whether the bacterial strain contributes to the sensory characteristics of sparkling wine is still questioned. The present work focuses on the population diversity of lactic acid bacteria isolated from two sparkling wine production regions: the famous Champagne in France and the rising region of Amyntaion in North of Greece. The molecular typing method of multiple loci VNTR analysis was used to type the bacterial strains based on five tandem repeats loci was used in the present work. According to our results the bacterial strains isolated from sparkling wine production regions are usually differentiated from the rest by forming distinct genetic subgroups. The adaptation mechanism of the species to the particular conditions of sparkling wine is also reflected at phenotypic level. This observed phenotype can confer selective advantages to the bacteria in such acidic environments as these wines, with potential effects on sparkling wine foamability.
Authors: Maria Dimopoulou (1,2), Margot Paulin (1), Olivier Claisse (1), George-John Nychas (2), Marguerite Dols-Lafargue (1,3)
1. Unité de recherche Oenologie, EA 4577, USC 1366 INRA, ISVV, Université de Bordeaux, Bordeaux INP, F33882 Villenave d’Ornon France
2. Laboratory of Food Microbiology and Biotechnology, Department of Food Science and Human Nutrition, Agricultural University of Athens, Greece
3. ENSCBP, Bordeaux INP, 33600 Pessac, France
Keywords: microbial terroir, sparkling wine, lactic acid bacteria, genetic diversity