[Effect of LED's red/blue light on the growth characteristic and lipid production of Scenedesmus sp. LX1].

Based on the theory that algal chlorophyll mainly absorbs red and blue light in the visual light, the effect of LED's red/blue light on the growth characteristic and lipid production of Scenedesmus sp. LX1 was studied. Under the same light intensity about 1400 lx, the specific growth rate of Scenedesmus sp. LX1 with LED (light emitting diode)'s red, blue and red-blue light are higher than that with normal white light by 15.8%, 13.2% and 18.4%, respectively. The algal density and population growth rate are also obviously higher than the ones with white light; among the three kinds of LED red/blue light, Scenedesmus sp. LX1 grows the fastest with red-blue light. On day 4.5 of cultivation, the algal density and population growth rate with LED's red-blue light is as highest as 2.7 and 3 times as that with white light, indicating the higher utilization efficiency of LED' s red/blue light and the enhancing effect on Scenedesmus sp. LX1's growth. With white light, LED's red, blue and red-blue light, the total lipid productivity of Scenedesmus sp. LX1 after 17 d of cultivation is 0.27 g x L(-1), 0.34 g x L(-1), 0.31 g x L(-1) and 0.28 g x L(-1), respectively; and the lipid content (dry weight) is 43.3%, 39.5%, 36.3% and 30.1%, respectively. Thus, with LED's red/blue light, the lipid content of Scenedesmus sp. LXI is a little lower while the growth is enhanced; however, the total lipid productivity is still relatively higher than that with white light.