Abstract:
Four strains of green microalgae (Scenedesmus acutus, Scenedesmus vacuolatus, Chlorella sorokiniana, and Chlamydomonas reinhardtii) were compared to determine growth and pigment composition under photoautotrophic or heterotrophic conditions. Batch growth experiments were performed in multicultivators with online monitoring of optical density. For photoautotrophic growth, light-limited (CO2-sufficient) growth was analyzed under different light intensities during the exponential and deceleration growth phases. The specific growth rate, measured during the exponential phase, and the maximal biomass productivity, measured during the deceleration phase, were not related to each other when different light intensities and different species were considered. This indicates species-dependent photoacclimation effects during cultivation time, which was confirmed by light-dependent changes in pigment content and composition when exponential and deceleration phases were compared. Except for C. reinhardtii, which does not grow on glucose, heterotrophic growth was promoted to similar extents by acetate and by glucose; however, these two substrates led to different pigment compositions. Weak light increased the pigment content during heterotrophy in the four species but was efficient in promoting growth only in S. acutus. C. sorokiniana, and S. vacuolatus exhibited the best potential for heterotrophic biomass productivities, both on glucose and acetate, with carotenoid (lutein) content being the highest in the former.
摘要:
四种绿色微藻(Scenedesmusacutus,空天眼,小球藻,和莱茵衣藻)进行了比较,以确定光自养或异养条件下的生长和色素组成。批量生长实验在复合机中进行,在线监测光密度。对于光合自养生长,在指数和减速生长阶段,在不同的光强度下分析了光限制(CO2充足)的生长。具体增长率,在指数阶段测量,和最大的生物量生产力,在减速阶段测量,当考虑到不同的光强度和不同的物种时,它们彼此不相关。这表明在培养期间依赖于物种的光驯化效应,当比较指数和减速阶段时,颜料含量和组成的光依赖性变化证实了这一点。除了C.Reinhardtii,它不会在葡萄糖上生长,乙酸盐和葡萄糖促进异养生长的程度相似;然而,这两种底物导致不同的颜料组成。弱光增加了这四个物种在异养过程中的色素含量,但仅在S.acutus中有效地促进了生长。C.Sorokiniana,空泡芽孢杆菌表现出最佳的异养生物量生产力潜力,葡萄糖和乙酸盐,类胡萝卜素(叶黄素)含量在前者中最高。