Metabolomics profiling reveals defense strategies of Pediococcus pentosaceus R1 isolated from Harbin dry sausages under oxidative stress

Abstract

The physiological performance and whole-cell metabolomic response of Pediococcus pentosaceus R1 to oxidative stress were investigated. The response to a sublethal concentration (3 mM) of H2O2 resulted in a time-dependent decrease in viable cells. After 1 h of oxidative stress, the level of reactive oxygen species (ROS) and the activities of antioxidant enzymes significantly increased (P < 0.05). Metabolomics analysis identified 74 metabolites as significant differentially metabolites (P < 0.05). The increased levels of amino acids were mainly involved in the supply of energy, and two major amino acids (l-glutamine and l-histidine) can act as antioxidants to protect the bacteria against oxidative stress. The accumulation of saccharides (d-galactose, d-glucose and d-maltose) may be an energy conservation strategy for the bacteria. The levels of saturated fatty acids (myristic acid, caproic acid and dodecanoic acid), which could prevent the entry of H2O2 by decreasing membrane fluidity, significantly increased (P < 0.05). This research facilitates understanding of the antioxidative mechanisms of P. pentosaceus R1 and will benefit the construction of engineering probiotics that can better tolerate stress factors when applied in food industrial processes.