Project description:Oenococcus oeni is the main lactic acid bacterium that carries out the malolactic fermentation in virtually all red wines and in some white and sparkling wines. O. oeni possesses an array of metabolic activities which can modify the taste and aromatic properties of wine. There is therefore industrial interest in the proteins involved in these metabolic pathways and related transport systems of this bacterium. In this work, we report the characterization of the O. oeni ATCC BAA-1163 proteome. Total and membrane protein preparations from O. oeni were standardized and analyzed by two-dimensional gel electrophoresis. Using tandem mass spectrometry we identified 226 different polypeptides corresponding to 155 unique proteins, which have been classified by their putative function and subjected to bioinformatics analysis.
Project description:Oenococcus oeni is the main lactic acid bacterium that carries out the malolactic fermentation in virtually all red wines and in some white and sparkling wines. Oenococcus oeni possesses an array of metabolic activities that can modify the taste and aromatic properties of wine. There is, therefore, industrial interest in the proteins involved in these metabolic pathways and related transport systems of this bacterium. In this work, we report the characterization of the O. oeni ATCC BAA-1163 proteome. Total and membrane protein preparations from O. oeni were standardized and analysed by two-dimensional gel electrophoresis. Using tandem mass spectrometry, we identified 224 different spots corresponding to 152 unique proteins, which have been classified by their putative function and subjected to bioinformatics analysis.
Project description:Lactic acid bacteria (LAB) are responsible for olfactory changes in wine during malolactic fermentation (MLF). A side characteristic of MLF is the release of grape derived aroma compounds from their glycosylated precursors by β-glycosidase activities of these bacteria. Apart from Oenococcus oeni, which is regarded as the most promising species for MLF, glycosidic activities have also been observed in wine related members of the genera Lactobacillus and Pediococcus. Nevertheless, information on the involved enzymes including their potential use in winemaking is limited. In this study we report that β-glucosidases with similar protein sequences can be identified in the genomes of Lactobacillus brevis, O. oeni and Leuconostoc mesenteroides. TTG serves as start codon for the glucosidase gene of O. oeni. The β-glucosidase of O. oeni ATCC BAA-1163 was expressed in E. coli and partially characterized. The enzyme displayed characteristics similar to β-glucosidases isolated from L. brevis and L. mesenteroides. A pH optimum between 5.0 and 5.5, and a K(m) of 0.17 mmol L(-1 )pNP-β-D-glucopyranoside were determined. A glycosyltransferase activity was observed in the presence of ethanol. The enzyme from O. oeni was capable to hydrolyze glycosides extracted from Muskat wine. This study also contains a report on glycosidase activities of several LAB species including Oenococcus kitaharae.
Project description:Oenococcus oeni strains are well-known for their considerable phenotypic variations in terms of tolerance to harsh wine conditions and malolactic activity. Genomic subtractive hybridization (SH) between two isolates with differing enological potentials was used to elucidate the genetic bases of this intraspecies diversity and identify novel genes involved in adaptation to wine. SH revealed 182 tester-specific fragments corresponding to 126 open reading frames (ORFs). A large proportion of the chromosome-related ORFs resembled genes involved in carbohydrate transport and metabolism, cell wall/membrane/envelope biogenesis, and replication, recombination, and repair. Six regions of genomic plasticity were identified, and their analysis suggested that both limited recombination and insertion/deletion events contributed to the vast genomic diversity observed in O. oeni. The association of selected sequences with adaptation to wine was further assessed by screening a large collection of strains using PCR. No sequences were found to be specific to highly performing (HP) strains alone. However, there was a statistically significant positive association between HP strains and the presence of eight gene sequences located on regions 2, 4, and 5. Gene expression patterns were significantly modified in HP strains, following exposure to one or more of the common stresses in wines. Regions 2 and 5 showed no traces of mobile elements and had normal GC content. In contrast, region 4 had the typical hallmarks of horizontal transfer, suggesting that the strategy of acquiring genes from other bacteria enhances the fitness of O. oeni strains.
Project description:Oenococcus oeni is the bacterial species that drives malolactic fermentation in most wines. Several studies have described a high intraspecific diversity regarding carbohydrate degradation abilities but the link between the phenotypes and the genes and metabolic pathways has been poorly described.A collection of 41 strains whose genomic sequences were available and representative of the species genomic diversity was analyzed for growth on 18 carbohydrates relevant in wine. The most frequently used substrates (more than 75% of the strains) were glucose, trehalose, ribose, cellobiose, mannose and melibiose. Fructose and L-arabinose were used by about half the strains studied, sucrose, maltose, xylose, galactose and raffinose were used by less than 25% of the strains and lactose, L-sorbose, L-rhamnose, sorbitol and mannitol were not used by any of the studied strains. To identify genes and pathways associated with carbohydrate catabolic abilities, gene-trait matching and a careful analysis of gene mutations and putative complementation phenomena were performed.For most consumed sugars, we were able to propose putatively associated metabolic pathways. Most associated genes belong to the core genome. O. oeni appears as a highly specialized species, ideally suited to fermented fruit juice and more specifically to wine for a subgroup of strains.
Project description:Oenococcus oeni is the most common species of lactic acid bacteria associated with malolactic fermentation in wine. Here, we report the genome sequence of the lytic phage OE33PA (vB_OeS_OE33PA). It has a morphotype similar to that of members of the Siphoviridae family, a linear 39,866-bp double-stranded genome with cohesive ends, and 57 predicted open reading frames.