Abstract: To explore the effects of different light equality on growth and phycocyanin accumulation of Spirulina, the algal cells were cultured in three monochromatic lights (i.e.white (W), blue (B), red (R) light) and their nine mixed light (mixed light intensity ratios) using light emitting diode (LED) as light source. Simultaneously, the algal yield, phycocyanin content and productivity were measured during the experimental period. The results showed that the red group promoted the growth rate of Spirulina, while the blue group contributed to improve both of phycocyanin content and purity in algal cells. Algal yield as optical density (OD) and dry weight in B+R (75%+25%) group increased by 154% and 157% compared with that in the blue group, whereas phycocyanin content and purity increased by 43% and 22% compared with that in the red group, respectively. OD value and dry weight in B+W (75%+25%) group were improved by 107% and 119%, respectively, compared to that in the blue group, but each of phycocyanin content and purity was almost same as that in blue group. The phycocyanin productivity in W+R (50%+50%) group was highest, 42 mg/（L·d）, among the tested groups.

Key words: LED, light quality, phycocyanin, biomass