In vivo bioluminescent determination of apparent K_m‘s for aldehyde in recombinant bacteria expressing luxA/B

Abstract

Recombinant bacteria which express only the luxA and luxB genes have a bioluminescent phenotype providing exogenous long chain aldehyde is supplied in the medium or as a vapour. As an integral part of the biochemistry of photon emission, sub‐saturating concentrations of aldehyde are reflected as sub‐maximal cellular bio‐luminescence. This may be correlated in a kinetic analysis to provide apparent Km values. An analysis of such data across a spectrum of Gram‐positive and Gramnegative bacteria was used to provide a limit for the sensitivity of aldehyde detection. The future development of a rapid bioluminescence‐based rancidity test in foods and oils is discussed.