The marine microalgae Isochrysis galbana was cultured under various light–emitting diode (LED) light conditions with different wavelengths to examine changes in growth and in amino acid and fatty acid profiles. The culture conditions for the microalgae were Conway medium, salinity of 33 psu, temperature of 24°C, and a 16/8 h light/dark photoperiod. Six light sources, including 5 units of 180W LED lamps (peak wavelength: blue [LB] 470 nm; green [LG] 525 nm; yellow [LY] 595 nm; red [LR] 636 nm; white [LW] 442 nm) and 1 unit of a 175W metal halide (MH) lamp, were used for the experiment. The dry cell weights (gL–1) of I. galbana under different light conditions were in the order of LW>LB≥MH>LR>LG>LY. Levels of essential amino acids were revealed to be significantly higher under LW, LG, and MH than under the other wavelengths (P<0.05). The fatty acid, unsaturated fatty acid, and DHA contents of I. galbana were higher under MH, LW, and LG. In addition, the carotenoid content was higher under MH, LW, and LG than under the other wavelengths (P<0.05). The fucoxanthin content was highest under MH (0.28%) and lowest under LY (0.2%), and it was 0.26% under LW and LG. The results indicate that the combined use of LW and LG is effective when using LED lamps for I. galbana cultivation.

• Jae–Hyun BAE(Fisheries Resources and Environment Research Division, East Sea Fisheries Research Institute, Gangneung 210–861, Korea) Corresponding author
• Heui–Chun AN(Fisheries Engineering Research Division, National Institute of Fisheries Science, Pusan 619–705, Korea)
• Heum–Gi PARK(Department of Marine Bioscience, Gangneung–Wonju National University, Gangneung 210–702, Korea)
• Jin–Chul PARK(East Coastal Life Science Institute Gangneung–Wonju National University, Gangneung 210–702, Korea)
• Jong–Myung PARK(Fisheries Resources and Environment Research Division, East Sea Fisheries Research Institute, Gangneung 210–861, Korea)
• Kyoung–Hoon LEE(School of Marine Production Management, Chonnam National University, Yeosu 550–749, Korea)
• Sung–Eic HONG(Bada Ecology Research, Gangneung 210–851, Korea)