Transcriptomic Analysis of the <i>Levilactobacillus brevis</i> 47f Strain under Oxidative Stress

Abstract

Levilactobacillus brevis 47f is a heterofermentative aerotolerant lactic acid bacterium isolated from the microbiota of the gastrointestinal tract of a healthy person. Previously, the strain showed anti-inflammatory properties and protects the murine intestine from enteropathy induced by 5-fluorouracil as part of preclinical studies. At the same time, the molecular mechanisms that account for the properties of the strain and its response to the action of reactive oxygen species, remain unexplored. The aim of this work was to study the response of the strain to the action of oxidizing agents – hydrogen peroxide and oxygen – using the method of transcriptional RNAseq analysis. Both oxidants exhibited a strong effect on the strain, increasing or decreasing the expression of several hundred genes – both general and specific for each oxidant. The characteristics of proteins whose expression was increased the most (DE ≥ 5) are provided. The genes activated under the action of both oxidants encode proteins related to stress, antioxidant activity, protein and nucleotide repair, cell wall, carbohydrate transport and metabolism, and catabolic energy storage pathways. Peroxide mainly activated the transcription of defense proteins, namely, stress response and molecular chaperones, antioxidant activity, DNA repair, and proteins involved in the formation of the cell wall. Under aerobic conditions, the genes that encode proteins involved in energy conversion (the use of fatty acids, nucleosides, fructose in addition to glucose as an energy source; proteins of the phosphoketolase pathway) and the import of peptides, amino acids, and sugars, were activated to a large extent. The data obtained in this work will be used by us to conduct an integrated analysis of transcriptomic, proteomic, and metabolomic data derived from this strain. This will make a significant contribution to the creation of a pharmacobiotic based on L. brevis 47f for the treatment of various inflammatory diseases.