The photosynthetic microalga Haematococcus pluvialis, a potential source of astaxanthin, was cultivated under illumination with LEDs
emitting red (λmax = 625 nm), green (λmax = 525 nm), blue (λmax = 470 nm), blue-purple (λmax = 410 nm) and purple (λmax = 380 nm)
light and a fluorescent lamp, and the effects of wavelength on cell growth and astaxanthin accumulation were studied. LEDs emitting light
of short wavelengths (380–470 nm) were found to induce astaxanthin accumulation of up to 5–6% per dry cell, although the induction
caused the suppression of cell growth. From these results, we proposed a new strategy of cultivating H. pluvialis under illumination with
red LEDs without inducing a high level of astaxanthin accumulation, and then switching to illumination with blue LEDs at a high light
intensity to induce a high level of astaxanthin accumulation