ISOLATION AND CHARACTERIZATION OF COMPACTIN RESISTANT MUTANTS OF AN ASTAXANTHIN SYNTHESIZING GREEN-ALGA HAEMATOCOCCUS-PLUVIALIS

Haematococcus pluvialis mutants resistant to compactin, an inhibitor f or 3-hydroxy-3-methylglutaryl coenzyme A reductase that is a key regul atory enzyme in the isoprenoid biosynthesis, were screened for higher astaxanthin producers. At 2 mM compactin, the wild type failed to grow , while two isolated mutants showed fairly good growth. In compactin-f ree medium, these resistant mutants have accumulated 1.4-2.0 fold high er astaxanthin than the wild type did. Based upon the specific enzyme activity assay, the mutant enzyme was found slightly less sensitive to compactin.