Abstract
In this paper, it was demonstrated that L-ascorbic acid was oxidized to dehydroascorbic acid by the L-ascorbic acid-oxidase in unadapted cells, and by the L-ascorbic acid-dehydrogenase in adapted cells. It was also found that the decomposing ability of L-ascorbic acid was lost in adapted cells when cells were not contacted with L-ascorbic acid for a long time, but was recovered again after some induction period when cells were contacted with L-ascorbic acid. On the other hand, from the results that L-ascorbic acid was decomposed by adapted cells of L-ascorbic acid but was not by adapted ones of D-araboascorbic acid, while 2-keto-L-gulonic acid was not by both adapted ones, it was concluded that L-form of C_5-OH group and endiol group in L-ascorbic acid molecule played important roles for the adaptive production of L-ascorbic acid decomposing enzyme system.