Isolation of disproportionating enzyme from halotolerant microalga Dunaliella parva (Volvocales, Chlorophyceae)

SUMMARY Starch metabolism in Dunaliella parva Lerche is regulated by the osmolarity of the surrounding solute. Two isozymes showing amylolytic activity were obtained after purification by gel filtration chromatography. The isozymes show disproportionating activity (D-enzyme) that is specific for malto-oligosaccharides as substrate. Properties of the D-enzyme in D. parva are similar to those in higher plants. The activity of the D-enzyme is also found in various Dunaliella and Chlamydomonas, indicating that the D-enzyme is also important in the starch metabolism in algae.