Riboflavin (vitamin B2) metabolism in bacteria encompasses both its biosynthesis and utilization as a precursor for cofactors such as flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are essential for numerous redox reactions. Many bacteria synthesize riboflavin de novo via a conserved pathway starting from guanosine triphosphate (GTP) and ribulose-5-phosphate. The pathway involves key enzymes like GTP cyclohydrolase II, which converts GTP to formate and 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone-5′-phosphate, followed by further modifications to form riboflavin. Once synthesized or acquired from the environment, riboflavin is phosphorylated by riboflavin kinase to produce FMN, which can subsequently be converted into FAD by FAD synthetase. These flavin cofactors play crucial roles in bacterial metabolism, including energy production in the electron transport chain, fatty acid β-oxidation, and oxidative stress responses. Some bacteria, particularly pathogens, rely on riboflavin uptake from their host via specific riboflavin transporters, making the metabolism and acquisition of riboflavin a potential target for novel antibacterial therapies. This pathway is not only vital for bacterial survival but also contributes to the ecological nutrient cycles through flavin biosynthesis and degradation.

Riboflavin metabolism References