DNA strands useful for the synthesis of xanthophylls and the process for producing the xanthophylls

Abstract

Disclosed are the following DNA strands relating to the synthesis of keto group-containing xanthophylls such as astaxanthin and the like, and the techniques relating to the production of xanthophylls by genetic engineering: A DNA strand having a nucleotide sequence which encodes a polypeptide having an enzyme activity for converting a methylene group at the 4-position of a .beta.-ionone ring into a keto group. A DNA strand having a nucleotide sequence which encodes a polypeptide having an enzyme activity for converting a methylene group at the 4-position of a 3-hydroxy-.beta.-ionone ring into a keto group. A DNA strand having a nucleotide sequence which encodes a polypeptide having an enzyme activity for adding a hydroxyl group to the 3-carbon of a 4-keto-.beta.-ionone ring. It is possible to produce a variety of xanthophylls such as canthaxanthin, astaxanthin and the like by introducing the DNA strands into an appropriate microorganism such as Escherichia coli and the like.

Dependencies are inferred from the claim text.