Abstract
FAD was comparatively stable in a highly concentrated solution against heating, while it was decomposed quickly in a dilute solution by boiling. Irradiation of ultraviolet rays and addition of metal ions such as Fe^<++>, Fe^<+++> and Mn^<++> accelerated the decomposition of FAD. On the other hand, the rate of decomposition of FAD was considerably decreased by addition of chloroform or p-cresol, or by heat sterilization. From these facts it was presumed that microorganisms in the air might participate in decomposing FAD in aqueous solution.
