[Effect of phenobarbital on the luminescence system of luminous bacteria]

The effect of phenobarbital on the luminescent system of Beneckea harveyi was studied. The inhibition of luminescence with phenobarbital was shown to be due to a disorder in the synthesis of an aldehyde factor, the endogenous substrate of bacterial luciferase. Upon the action of phenobarbital, the bacterium acquires the properties of "aldehyde" mutants, i. e. their luminescence is stimulated with exogenous decyl aldehyde. The luminescence of the cells was also stimulated with long-chain aldehydes, fatty acids and their analogues: apparently, the aldehyde factor is formed via incorporation of an oxygen atom into the terminal methyl of a saturated fatty acid or its analogue. Phenobarbital has no effect on the bacterial growth; however, it increases the content of luciferase in the culture. The results suggest that phenobarbital is not a direct inductor of luciferase synthesis. Possibly, the stimulating action of phenobarbital involves the inhibition of synthesis of the aldehyde factor and, consequently, an increase in the concentration of intermediate products of its synthesis.