Enhancement of cell biomass and cell activity of astaxanthin-rich Haematococcus pluvialis

Fed-batch culture and the transformation conditions of Haematococcus pluvialis in a 5 L photobioreactor were investigated. Methods of feeding model, low temperature at night and proper feeding time were used to increase both cell biomass and cell activity. Dry cell weight of 1.87 g/L which was 2.0-fold of batch culture and the specific growth rate of 0.43 d(-1) suggested the superduper results of these methods to increase the dry cell weight in the short cultivation time. Furthermore, mixed lights of blue and white (ratio of 3:1) at 7000 xl were used to expedite the morphologic changes of H. pluvialis from green cells to red cyst cells with the yield of 91.8 +/- 2.53 mg/L. (C) 2015 Elsevier Ltd. All rights reserved.