Superoxide dismutase plays an important role in the survival of Lactobacillus sake upon exposure to elevated oxygen

Abstract

In this study, the responses of two Lactobacillus sake strains to elevated oxygen concentrations at 8 degrees C were investigated. L. sake DSM 6333 (L. sake(sens)), unlike L. sake NCFB 2813 (L. sake(ins)), showed a low growth rate in the presence of 90% O(2) and a rapid loss in viability shortly after entry into stationary phase. The steady-state cytosolic superoxide radical (O(2)(-)) concentration in L. sake(sens) was 0.134 microM and in the oxygen-insensitive mutant LSUV4 it was 0.013 microM. The nine- to ten-fold decrease in the rate of O(2)(-) elimination in L. sake(sens) indicates the significance of the O(2)(-)-scavenging system in protecting against elevated O(2). The superoxide dismutase (SOD) activity was 10- to 20-fold higher in L. sake(ins) than in L. sake(sens), depending on the growth phase. An oxygen-insensitive mutant of L. sake(sens), designated as strain LSUV4, had a ten-fold higher SOD activity than the wild-type strain, which likely restored its oxygen tolerance. Damage to proteins in L. sake(sens) was evidenced by the increased protein carbonyl content and reduced activities of the [Fe-S]-cluster-containing enzymes fumarase and fumarate reductase. This study forms a physiological basis for understanding the significance of elevated oxygen stress as an additional method for inhibition of microbial growth in relation to food preservation.

Protective effects of probioticLactobacillus plantarumBJ0021 on liver and kidney oxidative stress and apoptosis induced by endosulfan in pregnant rats

“…61,62 The increased CAT and SOD activities we found in both liver and kidney were not statistically significant, consequently, we suggest that these enzymes would have a minor role in the inhibition of lipid peroxidation; therefore, the level of MDA was reduced probably with the increase of the scavenging rate of free radicals consequently to the enhancing of non-enzymatic defense, such as GSH (no determined here) or by other enzymes. Evidences have been shown that the antioxidant triad comprising SOD, CAT, and GPX constituted the first line of defense against the adverse effects of ROS.…”

Cystathionine γ-Lyase Is a Component of Cystine-Mediated Oxidative Defense in Lactobacillus reuteri BR11

“…Due to their lack of a heme biosynthesis pathway, LAB do not express fully functional catalases, but they have alternative mechanisms for oxidative defense. These include manganese-dependent pseudocatalase (25), superoxide dismutase (3,6,39,50,56), the alkyl hydroperoxide reductase system (15), and regulation of intracellular iron pool by Dpr (Dps-like peroxide resistance) (53). However, large gaps remain in the understanding of oxidative defense strategies in LAB, especially lactobacilli.…”

Purification and Characterization of an Arginine Aminopeptidase from Lactobacillus sakei

“…Therefore, the metabolic traits that allow this species to compete effectively in the meat ecosystem are under investigation (1,4,30). The proteolytic events that occur during meat processing lead to the generation of small peptides and free amino acids, which are considered to be flavor compounds (2,31).…”