高固碳、高油脂产率微拟球藻筛选

Screening of High Carbon Dioxide Fixing and Lipid Yielding Nannochloropsis oceanica Strains

随着全球经济快速发展,化石能源日益短缺、全球气候变暖问题日益突出,微藻生物柴油作为可再生能源逐渐取代传统化石能源,其研究已成为热点领域之一。微拟球藻(Nannochloropsis oceanica)生长速度快、油脂含量高且能固定一定浓度的CO2,已经实现了规模化养殖。本研究通过向柱状光生物反应器中通入10%CO2,从41株微拟球藻中筛选得到4株高固碳藻株,编号分别为E-099、Z-211、Z-213和Z-214。批次培养条件下,5株藻(4株高固碳藻株和出发藻株)分别通入空气、2%和5%CO2,随着CO2浓度升高,5株藻的生物量和固碳速率呈下降趋势,但总脂含量和油脂产率有所提高,总蛋白含量无显著差异。空气组(Air)中,出发藻株(WT)的生物量产率、固碳速率和油脂产率显著高于其它藻株,分别为0.07 g·L-1·d-1、0.16 g·L-1·d-1和49.012 mg·L-1·d-1;2%CO2下,藻株Z-213和Z-214的平均生物量产率、固碳速率和油脂产率显著高于其它藻株,分别为0.06 g·L-1·d-1、0.14 g·L-1·d-1和44.124 mg·L-1·d-1;5%CO2下,出发藻株的生物量产率、固碳速率和油脂产率显著低于其它藻株,而总蛋白含量却高达24%。本研究对藻株的固碳能力及经济价值进行了综合评价,为实现规模化利用提供参考。

With the rapid development of global economy, the depletion of fossil energy and the serious problem of global warming, microalgae as renewable energy biodiesel sources are becoming the research hotspots. Microalgal energy is expected to be an alternative of traditional fossil energy. Nannochloropsis oceanica grows rapid, fixes a large amount of CO2 and produces a high content of lipid, which has been farmed on large-scale successfully. In this study, four high carbon fixing and high lipid yielding E. oceanica strains(E-099, Z-211, Z-213 and Z-214) were screened from 41 strains by charging a columnar photobioreactor 10% CO2. Under batch culture, 5 strains(4 high carbon fixing and one wild) were cultured in air, 2% and 5% CO2, respectively. With the increase of CO2 concentration, the biomass yield and carbon fixation rate of the 5 strains showed a downward trend, but the total lipid content and lipid yield increased. There was no significant difference in total protein content among strains. When air was charged, the biomass yield, carbon dioxide fixation rate and lipid yield of WT were 0.07 g·L-1·d-1, 0.16 g·L-1·d-1 and 49.012 mg·L-1·d-1, significantly higher than those of other strains. When 2% CO2, was charged, the averages of biomass yield, carbon fixation rate and lipid yield of strains Z-213 and Z-214 were 0.06 g ·L-1·d-1, 0.14 g·L-1·d-1 and 44.124 mg·L-1·d-1, significantly higher than other strains. When 5% CO2 was charged, biomass yield, carbon fixation rate and lipid yield of wild strain were significantly lower than those other strains while the total protein content was 24%. In this study, the carbon fixation capacity and economic value of N. oceanica strains were comprehensively evaluated in order to provide a reference for its large-scale utilization.