The effective photoinduction of Haematococcus pluvialis for accumulating astaxanthin with attached cultivation

• H. pluvialis can accumulate effectively astaxanthin with this attached cultivation.
• Astaxanthin productivity of the attached system is 2.4-fold of that suspended.
• Attached cells can accumulate astaxanthin under low light and temperature up to 35 °C.
• This attached cultivation can strongly resist protozoan contamination.
• This attached cultivation is superior on saving water, ease to harvest.

As the optimal source of astaxanthin, Haematococcus pluvialis was cultured for commercial production of astaxanthin through two continuous phases: cell growth and astaxanthin induction. In this study, the efficiency of an attached system for producing astaxanthin from H. pluvialis was investigated and compared to that of the suspended system (bubble column bioreactor) under various conditions. Results showed that this attached system is more suitable for photoinduction of H. pluvialis than the suspended bioreactor. Under the optimal conditions, the astaxanthin productivity of the attached system was 65.8 mg m−2 d−1 and 2.4-fold of that in the suspended system. This attached approach also offers other advantages over suspended systems, such as, producing astaxanthin under a wide range of light intensities and temperatures, saving water, ease to harvest cells, resisting contamination. Therefore, the attached approach can be considered an economical, environmentally friendly and highly-efficient technology for producing astaxanthin from H. pluvialis.