Matching Light Source Spectrum to Photosynthetic Spectrum of Algae

Abstract

Microalgae have been utilized to produce various products such as pharmaceuticals, food additives, biofuels, and in processes like wastewater treatment and carbon dioxide fixation. However, scaling up production systems to provide necessary capacities of industrial scale remains a challenge. Photobioreactors, of this scale, have traditionally been limited to large open ponds or raceway systems, which require extensive land and produce low-density cultures. To achieve high-density cultures, closed systems must be developed by optimizing light, photosynthetic microorganisms, and nutrients. This study explores the optimization of light sources in photobioreactors to improve the efficiency of photosynthetic microorganisms used in various biotechnological applications. Various light sources, including LEDs, fluorescent, and incandescent lamps, were analyzed for their photon output and energy consumption at specific wavelengths crucial for photosynthesis. LEDs (with peak wavelength of 643nm) were found to be most efficient light source in the PAR range, particularly influencing the photosynthetic rates of microorganisms by converting electrical energy into useful photons, as determined by the antenna pigments of photosynthetic microorganisms. The research underscores the importance of selecting optimal lighting to enhance yields in microalgae-based production systems at lowest cost, suggesting a potential shift towards more efficient, controlled environmental conditions for higher productivity.