Genes have been isolated from strain DC260, a member of the Enterobacteriaceae family, encoding geranylgeranyl pyrophosphate (GGPP) synthetase (CrtE), phytoene synthase (CrtB), phytoene desaturase (CrtI), lycopene cyclase (CrtY), .beta.-carotene hydroxylase (CrtZ), and zeaxanthin glucosyl transferase (CrtX) activity. The genes and their products are useful for the conversion of farnesyl pyrophosphate to carotenoids. Vectors containing those DNA segments, host cells containing the vectors and methods for producing those enzymes by recombinant DNA technology in transformed host organisms are disclosed.