Quantitative Proteomics Analysis Confirmed Oxidative Metabolism Predominates in <i>Streptomyces coelicolor</i> versus Glycolytic Metabolism in <i>Streptomyces lividans</i>

Recent physiological studies indicated that <i>S. lividans</i> metabolism was mainly glycolytic, whereas <i>S. coelicolor</i> metabolism was mainly oxidative. To determine whether such metabolic characteristics were correlated with consistent proteomics features, a comparative label-free, shotgun proteomics analysis of these strains was carried out. Among 2024 proteins identified, 360 showed significant differences in abundance between the strains. This study revealed that <i>S. coelicolor</i> catabolized glucose less actively than <i>S. lividans</i>, whereas the amino acids present in the medium were catabolized less actively by <i>S. lividans</i> than by <i>S. coelicolor</i>. The abundance of glycolytic proteins in <i>S. lividans</i> was consistent with its high glycolytic activity, whereas the abundance of proteins involved in the catabolism of amino acids in <i>S. coelicolor</i> provided an explanatory basis for its predominantly oxidative metabolism. In this study, conducted under conditions of low O₂ availability, proteins involved in resistance to oxidative stress and those belonging to a DosR-like dormancy regulon were abundant in <i>S. coelicolor</i>, whereas tellurium resistance proteins were abundant in <i>S. lividans</i>. This indicated that the strains reacted differently to O₂ limitation. Proteins belonging to the CDA, RED, and ACT pathways, usually highly expressed in <i>S. coelicolor</i>, were not detected under these conditions, whereas proteins of siderophores, 5-hydroxyectoine, and terpenoid biosynthetic pathways were present.