内置LED光源平板型光生物反应器用于微藻培养——普通小球藻在反应器中的固碳产油性能探究

Internally LED-illuminated flat plate photobioreactor for microalgae cultivation-carbon-fixation and production of lipid in Chlorella vulgaris cultured in photobioreactor

为降低光生物反应器（PBR）的光照能耗和提高微藻对光能的利用效率,自制了内置LED光源的平板型光生物反应器,用于绿藻普通小球藻（Chlorella vulgaris）的培养和CO2生物固定.评价了这种新型反应器的进气CO2浓度对生物质产率（BP）、CO2固定速率（2COF）和油脂产率（LP）的影响.经过10d连续培养后,与通入空气的对照组相比,浓度1%~10%的CO2均明显促进微藻生长,BP[0.258和0.263g/（L d）]、最大2COF[1.18、1.00g CO2/（L d）]和指数生长期平均2COF[0.57、0.62g CO2/（L d）]的高值均出现在CO2 1%、2.5%处理组中.较高浓度（5%、10%）CO2在培养初期造成酸化现象,导致藻细胞密度和生物量较低.CO2浓度变化对微藻总脂含量（17.81%~23.13%）影响较小,以CO2 2.5%条件下得到微藻油脂产率最大[60.71mg/（L d）].本研究证明,所设计的平板型PBR能够高效培养用于CO2固定和生物柴油原料生产的微藻.

In order to improve the utilization efficiency of light by microalgae within a photobioreactor （PBR）, an internally LED-illuminated fiat plate PBR with volume of 3L was constructed and used for Chlorophyta （Chlorella vulgaris） in this study. Effects of the concentration of inlet CO2 on the biomass production （BP）, fixation efficiency of carbon （Fco2 ） and the production of lipid （LP） were evaluated. Biomass of microalgae in each treatment with concentration of CO2 ranging from 1% to 10% was higher than that of control with air （0.04% CO2） aeration in the cultures after 10-days growth. High levels of BP [0.258 and 0.263g/（L·d）], Fco2 [1.18 and 1.00gCO2/（L·d）] and average Fco2 [0.57 and 0.62gCO2/（L·d）] during the exponential growth stage were obtained under the concentration of CO2 at 1% and 2.5%, respectively. The cell density and biomass of microalgae were inhibited by the higher concentrations of CO2 （5% and 10%） during the initial growth stage because of acidification in cultures. Significant effects of CO2 concentrations on the production of lipid （17.81% - 23.13%） were not found here. The highest productivity of lipid [60.7 l mg/（L＇d）] was obtained under the concentration of CO2 at 2.5%. The present results suggested that the PBR used here was useful to improve CO2 biofixation and the production of lipid of microalgae.