Response ofEscherichia colicontaining mycobacterial carotene genes to UV radiation

Carotenoid pigments are largely distributed in nature. They are present in all of the photosynthetic organisms as well as in some bacteria, fungi, and yeast [1]. Two major biological roles have been assigned to carotenoids in plants and prokaryotes. In photosynthetic organisms, these pigments are involved in trapping light energy. A more general role applicable to both photosynthetic and non-photosynthetic cell, is protection from photodynamic action [1]. Genes controlling the synthesis of these pigments have been studied in several organisms such asErwiniaspecies [2,3,4],Mycobacterium aurumA+[5,6],Arabidopsis[7,8],Xantophyllomyces dendrorhous[9] andBrevibacterium linens[10].