Effects of indoor culture conditions on growth and phycoerythrin content of Proteomonas sulcata (Cryptophyta) assessed by flow cytometry

Abstract

The cryptophyte alga Proteomonas sulcata is rich in unsaturated fatty acids, phycoerythrin, and other biologically active substances and is suitable for aquatic feed, biomedical applications, and other related industries. To stimulate and increase the production of P. sulcata, we investigated the optimal culture conditions and two-stage culture of this alga under various factors (temperature, light intensity, and quality) using flow cytometry analysis. When cultivated at 24 degrees C with a light intensity of 100 mu mol photons m(-2) s(-1) and white light, the highest yield of biomass production was achieved (5.87 +/- 0.30 x 10(6) cells mL(-1)), while the highest relative index of phycoerythrin (i. e., phycoerythrin content) was obtained under green or red light. Although white light will result in the highest growth, red light could stimulate higher phycoerythrin content in cells. Finally, we suggested that flow cytometry could provide a dependable relative value of phycoerythrin content. This study is the first to confirm that flow cytometry can be used to collect physiological information on P. sulcata and sheds light on the optimal culture conditions for the growth of this alga.