A consensus is lacking whether monochromatic rather than broad-spectrum illumination is more efficient for photosynthetic microbe production platforms. Light wavelength and intensity were tuned to pigment composition for growth of the Cyanobacterium Synechocystis PCC 6803. Phycocyanin ( PC)targeting LEDs ( 620 nm) provided more than 6 times the peak efficiency of white LEDs, with peak efficiency growth rates of 0.063 h (1) at 81 mu E m (2) s (1) and 0.039 h (1) at 126 mu E m (2) s (1) for red and white LEDs, respectively. Chlorophyll a ( Chl a)-targeting LEDs ( 680- and 440-nm) performed poorly. Indeed, 10 times greater mass abundance was observed for PC than Chl a. PC levels did not change while Chl a levels decreased when Synechocystis transitioned from white light at 50 mu E m (2) s (1) to 250 mu E m (2) s (1) with 620 nm, 680 nm, or white LEDs. This work demonstrates that light wavelengths and intensity need to be optimized for each strain. (C) 2016 Elsevier Ltd. All rights reserved.