ISOLATION AND CHARACTERIZATION OF THE CAROTENOID BIOSYNTHESIS GENES OF FLAVOBACTERIUM SP STRAIN R1534

The Gram-negative bacterium Flavobacterium sp. strain R1534 is a natur al producer of zeaxanthin. A 14 kb genomic DNA fragment of this organi sm has been cloned and a 5.1 kb piece containing the carotenoid biosyn thesis genes sequenced. The carotenoid biosynthesis cluster consists o f five genes arranged in at least two operons. The five genes are nece ssary and sufficient for the synthesis of zeaxanthin. The encoded prot eins have significant homology to the crtE, crtB, crtY, crtI and crtZ gene products of other carotenogenic organisms. Biochemical assignment of the individual gene products was done by HPLC analysis of the caro tenoid accumulation in Escherichia coli host strains transformed with plasmids carrying deletions of the Flavobacterium sp. strain R1534 car otenoid biosynthesis cluster.