Regulation of Microbial Metabolism at the Gene and Protein Levels explores how microorganisms control their metabolic pathways through coordinated regulation at both genetic and protein levels. The book examines fundamental mechanisms such as transcriptional regulation, signal transduction, enzyme modification, and protein-protein interactions that enable microbes to adapt efficiently to changing environmental and nutritional conditions. By integrating molecular genetics, biochemistry, and systems biology perspectives, it highlights how gene expression and protein activity are tightly linked to metabolic flux and cellular physiology. The text also discusses modern experimental approaches, including omics technologies and regulatory network modeling, to understand microbial metabolism in a holistic way. This book is particularly valuable for researchers and graduate students in microbiology, biotechnology, and metabolic engineering who seek a deeper understanding of how metabolic regulation shapes microbial growth, survival, and industrial applications.