Haematococcus pluvialis gave the highest astaxanthin accumulation rate (2.7 mg l(-1) day(-1)) and total astaxanthin content ( 22.7 mg g(-1) biomass). Astaxanthin accumulation in Neochloris wimmeri, Protosiphon botryoides, Scotiellopsis oocystiformis, Chorella zofingiensis and Scenedesmus vacuolatus was, respectively, 19.2, 14.3, 10.9, 6.8 and 2.7 mg astaxanthin g(-1) biomass, respectively.