Reference Number: 152
Lactic Acid Bacteria: Prevalence
Aim: To determine the effect of several wine-associated, phenolic acids on the growth and viability of two bacterial lactobacilli strains called Oenococcus oeni and Lactobacillus hilgardii.
Methods: Growth was monitored in ethanol-containing medium supplemented with varying concentrations of hydroxybenzoic acids (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acids) and hydroxycinnamic acids (p-coumaric, caffeic and ferulic acids). Progressive inactivation was monitored in ethanol-containing phosphate buffer supplemented in a similar manner to the growth experiments. Hydroxycinnamic acids proved to be more inhibitory to the growth of O. oeni than hydroxybenzoic acids. On the other hand, some acids showed a beneficial effect on growth of Lact. hilgardii. p-Coumaric acid showed the strongest inhibitory effect on growth and survival of both bacteria.
Results: Most phenolic acids had a negative effect on growth of O. oeni but not Lact. hilgardii. For Lact. hilgardii this effect was only noted for p-coumaric acid. Generally, O. oeni was more sensitive to phenolic acid inactivation than Lact. hilgardii. Caffeic acid and ferric acids had the least inhibitory effects on both the lactobacilli strains with ferric acid stimulating the growth of lact.hilgardii.
SIGNIFICANCE OF THIS STUDY
Eight wine-derived, phenolic acids were compared for their effects on wine lactic acid bacteria. Results indicate that phenolic acids have the capacity to influence growth and survival parameters of lactobacilli strains of bacteria. The differences found between phenolic compounds could be related to their different chemical structures. Ferulic acid and caffeic acids investigated in this paper are polyphenols that are also present in wheat. The current study is an in-vitro study and therefore these findings cannot be directly applied in humans.