Abstract
Expectations for energy source shift from fossil fuels to renewable biofuels continue to grow.
Renewable bioproducts are also being developed for sustainable societies. Microalgae are ideal biomass
producers because their excellent characteristics surpass land plants; they grow much faster, can be
cultivated at unused hydrospheres, and accumulate a large quantity of such valuable compounds as lipids
and carotenoids. Many studies have been carried out to commercialize biomass production using
microalgae. To achieve sufficient cost-effectiveness, more useful microalgal strains must be obtained
and their cultivation conditions must be optimized. The recent development of various light-emitting
diodes (LEDs) has accelerated the understanding of the light effects of specific wavelengths on
microalgae. This review introduces the recent progress in the production of biofuels and carotenoids
using microalgae as well as discoveries about microalgal responses to light revealed by LEDs.
