Effect of Light on Nonphotosynthetic Microorganisms. IV. Photoinduced Carotenogenesis in Mycobacterium smegmatis

Although Mycobacterium smegmatis produces carotenoids when grown in the dark, the carotenoid production of this organism is enhanced by exposure to light. This enhancement consists of an initial photochemical reaction and a series of metabolic reactions (dark reactions) which lead to the enhancement of carotenoid synthesis. Inhibition experiments with chloramphenicol showed that the dark metabolic reactions following light exposure include the process of photoinduced protein synthesis. Thus, M. smegmatis is capable of light-independent and photoinduced carotenogenesis.