LAUSR

Some artificial light sources able to emit photons at specific wavelengths, such as LEDs, are useful for studying the effects of light quality on microalgal growth and production of fatty acids; however, they should not be used for outdoor cultivation of microalgae to produce bioenergy. Instead, various light filters capable of selectively transmitting red, blue, and red+blue light regions in solar radiation were used to cover 0.4 L bubble column photobioreactors to cultivate Tetraselmis sp. KCTC12236BP and investigate the influence of light quality on microalgal growth and fatty acid production. Biomass and fatty acid productivities in red light (0.10 ± 0.05 g/L/day and 11.8 ± 0.5 mg/L/day, respectively) were 7 ~ 53% and 9 ~ 61% higher than other colored lights based on the same number of supplied photons, respectively. The composition of fatty acids did not change significantly in response to transmitted light qualities of the filter. The ratio of saturated to unsaturated fatty acids was 3:7, and their contents were 12% in all groups, which corresponds with the results of LEDs. Plotting biomass and fatty acid productivity over the red photon fraction in supplied light revealed that increased productivities were closely correlated with red photon fraction in the filtered light. Overall, the results presented herein indicate that enhanced production of algal fatty acid could be achieved by application of light filters in outdoor settings without artificial lights.