Estimation of optimum specific light intensity per cell on a high-cell-density continuous culture of Chlorella zofingiensis not limited by nutrients or CO2

• Main Authors: Imaizumi, Yuki, Nagao, Norio, Md. Yusoff, Fatimah, Taguchi, Satoru, Toda, Tatsuki
• Format: Article
• Language: English
• Published: Elsevier 2014
• Online Access: http://psasir.upm.edu.my/id/eprint/37498/1/Estimation%20of%20optimum%20specific%20light%20intensity%20per%20cell%20on%20a%20high-cell-density%20continuous%20culture%20of%20Chlorella%20zofingiensis%20not%20limited%20by%20nutrients%20or%20CO2.pdf; http://psasir.upm.edu.my/id/eprint/37498/
• Institution: Universiti Putra Malaysia

To determine the optimum light intensity per cell required for rapid growth regardless of cell density, continuous cultures of the microalga Chlorella zofingiensis were grown with a sufficient supply of nutrients and CO2 and were subjected to different light intensities in the range of 75–1000 μE m−2 s−1. The cell density of culture increased over time for all light conditions except for the early stage of the high light condition of 1000 μE m−2 s−1. The light intensity per cell required for the high specific growth rate of 0.5 day−1 was determined to be 28–45 μE g-ds−1 s−1. The specific growth rate was significantly correlated to light intensity (y = 0.721 × x/(66.98 + x), r2 = 0.85, p < 0.05). A high specific growth rate was maintained over a range of light intensities (250–1000 μE m−2 s−1). This range of light intensities suggested that effective production of C. zofingiensis can be maintained outdoors under strong light by using the optimum specific light intensity.