Antioxidant properties of wine lactic acid bacteria: Oenococcus oeni

The most prominent trait of wine lactic acid bacteria (LAB) is their capacity to cope with a hostile environment. However, wine-derived LAB may confer inherent probiotic properties that have not been explored. In this study, the antioxidant activities of 19 strains of Oenococcus oeni were measured in vitro. The results suggested that the antioxidative parameters were widely dispersed, irrespective of the evaluation methods used, which indicated that antioxidative properties depended on the strain and culture medium. The antioxidant mechanisms of O. oeni could be assigned to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, reactive oxygen species (ROS) scavenging ability, iron ion chelation (FE), glutathione system, ferric reducing ability of plasma (FRAP), reduction activity (RA), inhibition of ascorbic oxidation (TAA), and linoleic acid oxidation (TLA) abilities. Moreover, most of the O. oeni strains exhibited good survival abilities at low pH values (pH 1.8), simulated intestine juice and bile salts (1 %), suggesting their good adaptation to gastrointestinal conditions and high bile resistance abilities. O. oeni SD-1e, SD-2gf, 31-DH, and SD-2d with promising potential probiotic characteristics were segregated by the principal component analysis (PCA). O. oeni strains likely serve as defensive agents in the intestinal microbial ecosystem and overcome exogenous and endogenous oxidative stress. Although further studies are needed to elucidate the multiple mechanisms involved, the study reported herein confirms the effectiveness of O. oeni in the defense against in vitro oxidative stress.