Simultaneous accumulation of astaxanthin and β-carotene in Chlamydomonas reinhardtii by the introduction of foreign β-carotene hydroxylase gene in response to high light stress.

Carotenoids are important photosynthetic pigments with many physiological functions, nutritional properties and high commercial value. β-carotene hydroxylase is one of the key enzymes in the carotenoid synthesis pathway of Chlamydomonas reinhardtii for the conversion of β-carotene to astaxanthin. The vector p64DZ containing the β-carotene hydroxylase gene crtZ from Haematococcus pluvialis was transformed into C.