Reaction of <i>Bifidobacterium longum</i> subsp. <i>infantis</i> Strain ATCC 15697 to Oxidative Stress

Abstract

The genus Bifidobacterium is one of the predominant bacterial populations in human gut microbiota. Despite the increasing number of studies on the beneficial functionality of bifidobacteria for human health, knowledge about their antioxidant potential is still insufficient. The role of the antioxidant potential of bifidobacteria in maintaining the homeostasis of the intestinal microbiota of the host organism as a whole is an important task that requires solutions. For the first time, this paper presents the data of genomic, transcriptomic and proteomic analyses of probiotic strains Bifidobacterium longum subsp. infantis ATCC 15697 after the action of oxidative stress. The growing culture of strain was exposed to hydrogen peroxide for 2 hours and oxygen for 2 and 4 hours. Preliminary genome analysis of the strain showed the presence of 18 genes encoding a known protein with antioxidant function, as in other complied genomes of B. longum subsp. infantis strains available in the international database. The complete transcriptome analysis revealed an increase in transcript levels by more than two times for 6 genes with a known antioxidant function. The data of quantitative proteomic analysis showed an increase in protein levels by more than two times for five enzymes with a known antioxidant function. 28 other proteins with increased levels more than twice were identified in the cells of the growing culture in response to the long action of oxygen. These proteins can be involved in the processes of the cell’s response to stress, the amino acids, nucleotides metabolism and transport processes. Six proteins with unknown functions, which may play a significant role in the antioxidant response of anaerobic bifidobacteria, were found to have high levels in the cells after the action of stress. The obtained data are supposed to be used in the selection of B. longum subsp. infantis strains and the creation of pharmacobiotics able to correct the composition of the microbiota.