Oxygen evolution rate of photosynthetic microalga Haematococcus pluvialis depending on light intensity and quality

The green microalga Haematococcus pluvialis has a potential for production of an antioxidant astaxanthin (3,3'-dihydroxy-beta,beta'-carotene-4,4'-dione) from carbon dioxide as a carbon source. Therefore, this alga has been studied as a model microorganism for fixation of carbon dioxide and for production of value-added chemicals. In this study, a system for the measurement of photosynthetic activity of microalgae was developed and used for evaluating the effects of light quality and spectra on the oxygen evolution rate of H. pluvialis. The photosynthetic activity was measured by the system using various types of sun light, green, and red light filters. As increasing the light intensity, the photosynthetic activity increased and eventually reached a maximum value, e.g., 59.7 +/- 2.3 mg g(-1) h(-1) under red light condition at 0.123 g L-1 of cell concentration. However, each photosynthesis-irradiation curves were different at the same light intensity because these microalgae absorb selectively the light that could be used easily for photosynthesis.