Identification of possible light emitters in the gills of a bioluminescent fungus Mycena chlorophos

The pileus of Mycena chlorophos actively, spontaneously, and continuously emits green light. Molecular mechanisms underlying this bioluminescence remain unclear. We investigated light emitters in the pileus of M. chlorophos to determine the underlying mechanisms. High‐performance liquid chromatography–fluorescence–photodiode array–mass detection analyses showed that actively luminescent gills in the pileus exclusively and abundantly possessed riboflavin, riboflavin 5′‐monophosphate, and flavin adenine dinucleotide as green‐fluorescent components. These components were localized in the bioluminescent region of the gills at the microscopic level. Fluorescence spectra of these green‐fluorescent components and the gills were identical with the spectrum of gill bioluminescence (maximum emission wavelength, 525 nm). Thus, our results indicated that the possible light emitters in the pileus of M. chlorophos were riboflavin, riboflavin 5′‐monophosphate, and/or flavin adenine dinucleotide. Copyright © 2016 John Wiley & Sons, Ltd.