Global transcriptomic analysis of Lactobacillus plantarum CAUH2 in response to hydrogen peroxide stress

To overcome the deleterious effects of hydrogen peroxide, Lactobacillus plantarum elicits an adaptive response to oxidative stress. In this study, global transcriptomic analysis revealed that L. plantarum CAUH2 expanded its carbon source utilizing profile and enhanced glycolysis to produce more ATP to confront with H2O2 stress. Some antioxidant enzymes including NADH peroxidase, thioredoxin reductase and glutathione peroxidase were 6.11, 36.76 and 6.23-fold up-regulated at transcription level for H2O2 scavenging. Meanwhile, free ferrous iron (Fe2+) was maintained at low concentrations in the cytoplasm, which could limit Fenton reaction and reduce the production of hydroxyl radicals. To repair DNA lesion caused by H2O2, both base excision repair system and recombinational DNA repair pathway were employed by L. plantarum CAUH2. In addition, the expression of methionine sulfoxide reductases and thioredoxin were up-regulated to repair oxidized proteins. It is noteworthy that some transcriptional regulators (Spx, CcpA and MarR1) were predicted to participate in the adaptive response to H2O2 stress, suggesting that L. plantarum CAUH2 utilized a wide array of sensors to monitor oxidative stress and modulated the transcriptional regulation network under H2O2 stress. These findings provide novel insight into the protective mechanisms developed by L. plantarum to cope with oxidative stress.