Effect of tannic acid on Lactobacillus plantarum wine strain during starvation: A proteomic study

The molecular mechanisms involved in tannic-acid (TA)-mediated cell growth retardation and viability prolongation of Lactobacillus plantarum VP08 strain were evaluated by a proteomic analysis of starved cells grown in the presence of TA or glucose as carbon source. The tannase activity and the cell growth retardation as well as viability prolongation were confirmed by enzymatic assay and growing tests, respectively. In order to gain information about the effect triggered at the molecular level by TA, total proteins (extracted from starved cells grown in 250 mg/L TA, or 2 g/L glucose) were analyzed by a 2D-PAGE/MS approach to detect differentially expressed proteins. A total of 15 spots were found to be down-regulated and 21 up-regulated in TA-grown cells. The results indicate an overall impact of TA on proteins involved in some cellular and metabolic pathways: glycolysis, amino acid metabolism, translation and protein folding. The modulation of specific proteins correlates with the positive effect of TA on the survival of tannase-positive L. plantarum.