Characterizing arginine, ornithine, and putrescine pathways in enteric pathobionts

The amino acid L-arginine is converted by bacteria into a variety of downstream metabolites, including citrulline, agmatine, ornithine, putrescine, and gamma-aminobutyric acid (GABA). Our study shows that both Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Klebsiella aerogenes, Pseudomonas fluorescens, andAcinetobacter baumannii) and Gram-positive bacteria (Streptococcus agalactiae, Staphylococcus epidermidis, Staphylococcus aureus, andEnterococcus faecalis) consume arginine, glutamine, and glutamate, and generate citrulline, ornithine, and GABA. This suggests that these pathways are conserved and essential within gut bacteria. We also found thatEscherichia coli, Klebsiella pneumoniae, Klebsiella aerogenes, andPseudomonas fluorescens generate the arginine intermediate agmatine and produce the polyamine putrescine. These findings indicate that arginine is a crucial amino acid for gut bacteria. AbstractArginine-ornithine metabolism plays a crucial role in bacterial homeostasis, as evidenced by numerous studies. However, the utilization of arginine and the downstream products of its metabolism remain undefined in various gut bacteria. To bridge this knowledge gap, we employed genomic screening to pinpoint relevant metabolic targets. We also devised a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics method to measure the levels of arginine, its upstream precursors, and downstream products in cell-free conditioned media from enteric...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research