Analysis of the Growth and Metabolites of a Pyruvate Dehydrogenase Complex-Deficient Klebsiella pneumoniae Mutant in a Glycerol-Based Medium

Abstract

To determine the role of pyruvate dehydrogenase complex (PDHC) in Klebsiella pneumoniae, the growth and metabolism of PDHC-deficient mutant in glycerol-based medium were analyzed and compared with those of other strains. Under aerobic conditions, the PDHC activity was fourfold higher than that of pyruvate formate lyase (PFL), and blocking of PDHC caused severe growth defect and pyruvate accumulation, indicating that the carbon flux through pyruvate to acetyl coenzyme A mainly depended on PDHC. Under anaerobic conditions, although the PDHC activity was only 50% of that of PFL, blocking of PDHC resulted in more growth defect than blocking of PFL. Subsequently, combined with the requirement of CO 2 and intracellular redox status, it was presumed that the critical role of PDHC was to provide NADH for the anaerobic growth of K. pneumoniae. This presumption was confirmed in the PDHC-deficient mutant by further blocking one of the formate dehydrogenases, FdnGHI. Besides, based on our data, it can also be suggested that an improvement in the carbon flux in the PFL-deficient mutant could be an effective strategy to construct highyielding 1,3-propanediol-producing K. pneumoniae strain.

Reprogramming Short-Chain Fatty Acid Metabolism Mitigates Tissue Damage for Streptococcus pyogenes Necrotizing Skin Infection

“…Due to its role in regulation of DT, PDH becomes an attractive target for therapeutic interventions in severe invasive diseases. In addition to S. pyogenes, PDH is critical for the growth of numerous pathogenic bacteria [48,49]. PDH is an enzyme complex that converts pyruvate into acetyl-CoA, which consists of three enzymes [5].…”