D-Amino acid metabolism in bacteria

Abstract

Bacteria produce diverse d-Amino acids, which are essential components of cell wall peptidoglycan. Incorporation of these d-Amino acids into peptidoglycan contributes to bacterial adaptation to environmental changes and threats. d-Amino acids have been associated with bacterial growth, biofilm formation and dispersal and regulation of peptidoglycan metabolism. The diversity of d-Amino acids in bacteria is primarily due to the activities of amino acid racemases that catalyse the interconversion of the d-and l-enantiomers of amino acids. Recent studies have revealed that bacteria possess multiple enzymes with amino acid racemase activities. Therefore, elucidating d-Amino acid metabolism by these enzymes is critical to understand the biological significance and behaviour of d-Amino acids in bacteria. In this review, we focus on the metabolic pathways of d-Amino acids in six types of bacteria.