Characterization of an AsnC/Lrp-family transcriptional regulator in

Introduction: The mutation of Methods: Quantitative GC-FID analyses, fluorescence microscopy, and gene expression analysis were used to evaluate PHB metabolism, intracellular granule formation, and transcriptional responses under nitrogen-replete and nitrogen-limited conditions. Results: Quantitative GC-FID analyses revealed a dynamic accumulation-consumption cycle of PHB in the wild-type strain, whereas the hr0242:Tn5 mutant exhibited reduced production, impaired turnover, and earlier depletion of intracellular reserves. Although both strains synthesized PHB under nitrogen-replete and nitrogen-limited conditions, accumulation was less sustained in the mutant, indicating compromised storage capacity. Fluorescence microscopy confirmed the presence of intracellular granules in both strains, with lower intensity and frequency in the mutant. Gene expression analysis revealed coordinated regulation of genes involved in PHB metabolism in the wild type according to nitrogen availability, whereas the mutant exhibited reduced Discussion: Together, these findings demonstrate that