The impact of various light spectra on the size of Spirulina platensis cells

These days the use of microalgae in food, pharmaceutical, and cosmetic industry is on the increase. Microalgae are miraculous sources including high percentage of proteins, various types of pigments, and other vital components for body such as amino acids, carbodydrates and fatty acids. This study aimed at evaluating the cultivation and changes in cell sizes of Spirulina platensis a kind of blue-green algae under various qualities of light spectra including red, yellow, blue, and white with 150 µmolphotons. m-2. s-1 light intensity and 12-12 light/dark cycle. The highest amount of biomass was produced under red light, against the blue light produced the lowest biomass. The effect of various light wavelengths on the size of cells showed that the length of cells is against the biomass accumulation. Therefore, the red light produced the highest amount of biomass with the shortest length of cells and the blue light caused the least number of cells with largest size to produce. Overall, the effect of different light spectra on the biomass production and cell size summarized as follows: biomass: red˃ white˃ yellow ˃ blue, cell size: blue˃ yellow˃ white˃ red.