THE EFFECT OF SUBLETHAL DOSES OF ARTIFICIAL SUNLIGHT ON ADAPTIVE ENZYME SYNTHESIS BY ESCHERICHIA COLI

Abstract

The effect of sublethal doses of artificial sunlight and individual wavebands of light on the ability of Escherichia coli to synthesize the enzymes concerned in lactose oxidation have been studied. It was found that direct sunlight completely inhibited enzyme synthesis but did not affect the action of preformed enzymes. Blue and yellow light were both active in preventing enzyme synthesis but the blue region of the spectrum was by far the most effective. No effect of red light could be demonstrated. Staining cells with yellow or red dyes reduced the action of blue light whereas staining the cells with a blue dye increased the effectiveness of yellow light.