earticle

영어

Enzymes utilizing maltodextrin and glycogen in bacteria were studied to investigate their roles in maltodextrin and glycogen metabolism. Bacillus subtilis mutants deficient maltogenic amylase (ΔyvdF) and/or pullulanase (ΔamyX) were constructed. A series of Escherichia coli mutants lacking MalP (maltodextrin phosphorylase), MalZ (maltodextrin glucosidase), MalQ (4-α-glucanotransferase), and/or GlgA (glycogen synthase) were constructed, and the glycogen produced from the mutants of E. coli and B. subtilis was analyzed. The data on the amount, the structure, and hydrolysis rate of the glycogen from Bacillus mutants revealed that the maltogenic amylase and the pullulanase have a significant role in the synthesis as well as the degradation of the glycogen. In the E. coli mutant lacking the glycogen synthase, glycogen was synthesized from the maltose by the action of MalQ. E. coli MalPmutant accumulated 20 times greater amount of glycogen than the wild type, and the result implies that MalP controlled the glycogen accumulation of the MalQ-dependant pathway. In conclusion, the maltodextrin and the glycogen metabolism in bacteria are tightly interconnected by the actions of the glycoside hydrolases.