Proteomic analysis of Oenococcus oeni freeze‐dried culture to assess the importance of cell acclimation to conduct malolactic fermentation in wine

Abstract

Cultures of Oenococcus oeni, the most important malolactic bacterium, are used to induce malolactic fermentation in wine. Survival assays in two different wines confirmed that cells acclimated for 24 h in half-strength wine-like medium (acclimation medium) enhanced the malolactic performances. To investigate the effect of the pre-incubation phase on cell physiology, a proteomic study was carried out. Total protein extracts of acclimated and non-acclimated cell cultures (control) were analyzed by 2-D-PAGE. A total of 20 out of approximately 400 spots varied significantly. All the spots were identified by MS analysis and most of them were proteins involved in metabolism, transcription/translation processes and stress response. The results revealed the different physiological status between non-acclimated and acclimated cells explaining, in part, their different behavior in wine. Regulation of stress proteins such as heat and cold shock proteins was involved. Moreover, the availability of sugars and amino acids (even if at low concentration) in acclimation medium determined a modulation of energy metabolism enhancing the resistance to stressful conditions (as those that cells find in wine when inoculated). Finally, this proteomic study increased knowledge concerning the physiological changes in freeze-dried culture occurring with pre-inoculation procedures.

Transcriptomic and proteomic analysis of Oenococcus oeni PSU-1 response to ethanol shock

“…These two genes could therefore be useful molecular reporters of the metabolic state of cells in response to ethanol stress. Cecconi et al (2009) reported a similar result for one of these proteins, glucosamine 6-phosphate aminotransferase (OEOE_0635), which was less abundant in cells not acclimated to ethanol (as in the present study) than in acclimated cells. Thus we might suggest that the non-activation of these genes indicate cellular metabolic robustness against the induced stress.…”

“…For instance, Silveira et al (2004) found that ethanol triggers alterations in the protein patterns of O. oeni cells that are directly stressed with 12% ethanol for 1 h and cells pre-adapted in 8% ethanol. It has also been shown that cell cultures acclimated with 10% ethanol survived better in wine, probably due to the differential expression of certain proteins (Cecconi et al, 2009). Functional analysis of gene expression using comparative transcriptomics is also providing insight into stress responses and regulation mechanisms in lactic acid bacteria (LAB).…”

Effect of acclimation medium on cell viability, membrane integrity and ability to consume malic acid in synthetic wine by oenologicalLactobacillus plantarumstrains

“…Previous papers reported that acclimation in media containing ethanol within 4 and 10% v/ v (Cecconi et al 2009;Solieri et al 2009;Lerm et al 2010) and low pH (from 3Á5 to 4Á6) can increase the ethanol resistance during winemaking. The results obtained in this work showed that acclimation in the presence of 6 and 10% v/v ethanol improves the cultivability and L-malic acid consumption in synthetic wine.…”

“…Different physicochemical and biological parameters (i.e. low pH, high ethanol concentration, SO 2 tolerance, yeasts-bacteria interactions) can inhibit bacterial growth, undergoing a high rate of mortality, and consequently, the failure of MLF (Cecconi et al 2009).…”

A partial proteome reference map of the wine lactic acid bacterium Oenococcus oeni ATCC BAA-1163

“…Two-dimensional gel analysis of total cellular proteins provides a global overview on the real biological response under specific conditions. Currently, only few comparative analyses of O. oeni proteomes have been reported [15–17]. Detection of 81 out of 186 differently expressed peptides was observed during starvation conditions, although none of the differently expressed spots were identified [16].…”