| 摘要 |
<p>The following DNA chains relate to xanthophylls having a keto group, represented by astaxanthin, and the following technique relates to a genetically engineered production of xanthophylls: a DNA chain having a base sequence coding for a polypeptide having an enzymatic activity of converting the 4-methylene group of a β-ionone ring into a keto group; a DNA chain having a base sequence coding for a polypeptide having an enzymatic activity of converting the 4-methylene group of a 3-hydroxy-β-ionone ring into a keto group; a DNA chain having a base sequence coding for a polypeptide having an enzymatic activity of adding a hydroxyl group to the 3-carbon atom of a 4-keto-β-ionone ring; and a process for producing various xanthophylls, such as canthaxanthin and astaxanthin, by introducing the above DNA chain(s) into a suitable microorganism, e.g., Escherichia coli, followed by expression thereof.</p> |
