CcpA-Mediated Enhancement of Sugar and Amino Acid Metabolism in Lysinibacillus sphaericus by NMR-Based Metabolomics

Lysinibacillus sphaericus is a bacterium incapable of metabolizing sugars with the sole exception of N-acetylglucosamine. To unravel the regulatory role of catabolite control protein A (CcpA) in the sugar metabolism of L. sphaericus, a ccpA deficient mutant was constructed by homologous recombination. The mutant showed growth deficiency and a low efficiency of carbon and energy utilization. NMR spectroscopy in combination with multivariate data analysis revealed that the metabolome of L. sphaericus was dominated by 25 metabolites mainly including amino acids, carbohydrate derivatives and organic acids, and that the mutation of the ccpA gene caused significant reduction of leucine, valine, alanine, threonine, glutamate, lysine, d-ornithine, tyrosine, uridine 5'-diphospho-N-acetlyglucosamine formate, fumarate, phenylalanine, aspartate, asparagine, and acetate but elevation of ribose-5-phosphate, and uracil. Furthermore, the networks of CcpA-mediated regulation based on the metabolome were constructed by arrangement of significantly decreasing or increasing metabolites. The network map suggests CcpA regulates and promotes sugar and amino acid metabolism of L. sphaericus.