A large number of Photobacterium phosphoreum (6-7 log/g) was isolated from “tamagoyaki” (a kind of nigirisushi; Japanese food) that had been lumineferous in the dark. The isolates were smeared on the surfaces of sliced “tamagoyakis”. After the incubation at 10°C for 48 hr or at 25°C for 24 hr, the surfaces became luminous. It was indicated that this abnormality of “tamagoyaki” was caused by contam