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This study investigates the effects of simultaneous inoculation of a selected Saccharomyces cerevisiae yeast strain with two different commercial strains of wine bacteria Oenococcus oeni at the beginning of the alcoholic fermentation on the kinetics of malolactic fermentation (MLF), wine chemical composition, and organoleptic characteristics in comparison with spontaneous MLF in Tempranillo grape must from Castilla-La Mancha (Spain). Evolution of MLF was assessed by the periodic analysis of L-malic acid through the enzymatic method, and most common physiochemical parameters and sensory traits were evaluated using a standardized sensory analysis. The samples were analyzed by GC/MS in SCAN mode using a Trace GC gas chromatograph and a DSQII quadrupole mass analyzer. Co-inoculation reduced the overall fermentation time by up to 2 weeks leading to a lower increase in volatile acidity. The fermentation-derived wine volatiles profile was distinct between the co-inoculated wines and spontaneous MLF and was influenced by the selected wine bacteria used in co-inoculation. Co-inoculation allows MLF to develop under reductive conditions and results in wines with very few lactic and buttery flavors, which is related to the impact of specific compounds like 2,3-butanedione. This compound has been also confirmed as being dependent on the wine bacteria used. [ABSTRACT FROM AUTHOR]

The Oenococcus oeni populations of Tempranillo wines from Castilla La Mancha and La Rioja winemaking regions were analysed from one to three years and up to ten wineries. The objective was to evaluate the genetic variability and the O. oeni population structure. For this purpose a MLST scheme based on four loci ( gyr B, pur K, pgm and recP genes) and PFGE with Sfi I restriction enzyme were developed for later combination. The results showed an O. oeni population completely adapted to winemaking regions. A purifying selection influenced the genes evolution, especially recP that along with purK were the most interesting loci to analyse the genetic variability of the isolates. In this way linkage disequilibrium and intergenic and intragenic recombination were determined between isolates. PFGE typing with UPGMA data were not coincident with the phylograms assessed for MLST by Maximum likelihood and combination of both techniques differentiated all the isolates as strains. Those results led the research to conclude that O. oeni population from CM and LR was a panmictic population with a slight clonal evolution, so subpopulations could not be described. A broader study including more winemaking regions with different grape varieties and distinct ways of elaborating would be interesting to complete the knowledge about O. oeni populations. [ABSTRACT FROM AUTHOR]

Abstract: The ecology and the population dynamics of lactic acid bacteria during malolactic fermentation of Tempranillo wine made at five wineries in Castilla-La Mancha were analysed for two consecutive vintages (years 2006 and 2007). This microbiota was typed using Randomly Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) subsequently identified using both molecular and phenotypic methods. Oenococcus oeni was the predominant species. Genotypes varied considerably in both of the vintages from each winery, although a number of coincident genotypes were found in each one. Three genotypes were present in all the wineries in at least one of the vintages. These results confirm the existence of a coincident population of O. oeni genotypes that may be considered endemic to this wine region and that seem to play an important role in all the vinifications. [Copyright &y& Elsevier]

Abstract: The genetic diversity of 339 strains of lactic acid bacteria responsible for the spontaneous malolactic fermentation (MLF) in Tempranillo wines produced in six cellars located in different provinces of Castilla-La Mancha region of Spain was analyzed by using randomly amplified polymorphic DNA (RAPD). The results indicate that Oenococcus oeni was the predominant species in MLF of Tempranillo wines with a scant diversity of other lactic acid bacteria (LAB) species. The presence of a well-adapted cellar microbiota is confirmed, with MLF dominated by a limited number of O. oeni genotypes. Clustering of isolates from samples taken from different provinces showed the existence of coincident genotypes in different cellars of the region. This result suggests that a population of cosmopolitan O. oeni strains exists in the Castilla-La Mancha wine-growing region. [Copyright &y& Elsevier]