(17e) Interactive Effect of Temperature, Light Quality and Intensity on Algae Growth and Nutrient Composition

Growing algae for food, carbon dioxide fixation, and water purification would make long-range space travel more feasible. This work focuses on the interactive effect of light quality (spectral distribution of light), intensity and temperature. The green alga strain Chlamydomonas reinhardtii was grown in batch cultures in a constant temperature shaker. A multi-wavelength LED light was used as light source. The influence of different light spectra and temperature on growth kinetics and nutrient composition was collected and analyzed for two algae growth phases. The results indicate that both temperature and light quality are important for growth rates and nutrient composition. No “threshold” effect of blue light on algae growth was observed. White-yellow light which represents the spectra combination of blue-green-yellow light favored the specific growth rate under light intensity of 106 μmol/m²s and four temperatures (24-32ºC) tested. Blue light or lower temperatures favored the protein content; red-orange light or higher temperatures favored the carbohydrate and lipid content. Light intensity (40-300 μmol/m²s) had complex effect on growth and nutrient composition, of which the variation trend with intensity was different under different light qualities.