Reaction of Bifidobacterium longum subsp. infantis Strain ATCC 15697 to Oxidative Stress

The genus Bifidobacterium is one of the most predominant bacterial populations in human-gut microbiota. Despite the increasing number of studies on the beneficial properties 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, transcriptome, and proteomic analyses of Bifidobacterium longum subsp. infantis ATCC 15697 strain after the action of oxidative stress. A growth culture of the strain is exposed to hydrogen peroxide for 2 hours and oxygen for 2 and 4 hours. Preliminary genome analysis of the strain shows the presence of 17 genes encoding a known protein with antioxidant function, as in other genomes of B. longum subsp. infantis available in the international database NCBI. Complete transcriptome analysis reveals an increase in the transcript levels by more than two times for 6 genes with a known antioxidant function. The data of quantitative proteomic analysis shows an increase in protein levels by more than two times for five enzymes with a known antioxidant function. Over 28 other proteins with levels increased by more than two times are identified in the cells of the growth culture in response to the long-term action of oxygen. These proteins can be involved in the processes of the cell's response to stress, amino-acid- and nucleotide metabolism, and transport processes. Six proteins with unknown functions, which may play a significant role in the antioxidant response of anaerobic bifidobacteria, are 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 pharmabiotics able to correct the composition of the microbiota.