Oxygen Affinities of the Bioluminescence Systems of Various Species of Luminous Bacteria

Summary: O2 affinities of the bioluminescence systems have been measured in five species of luminous bacteria. Photobacterium phosphoreum He-1a, recently isolated from a fish light-organ, showed halfmaximal bioluminescence at 0·015 µM-O2 whereas another symbiotic strain (PJ-1a) gave a 33-fold higher value. Vibrio fischeri MJ-1 gave a value of 0·60 µM-O2, and the symbiotic Photobacterium leiognathi LN-la gave half maximal emission at 0·7 µM-O2. These results indicate the importance of strain selection for sensitive O2 measurements.