Hulatt Chris J, Wijffels René H, Bolla Sylvie, Kiron Viswanath
Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway.
Bioprocess Engineering, AlgaePARC, Wageningen University, Wageningen, The Netherlands.
PLoS One. 2017 Jan 19;12(1):e0170440. doi: 10.1371/journal.pone.0170440. eCollection 2017.
Nannochloropsis is an industrially-promising microalga that may be cultivated for alternative sources of nutrition due to its high productivity, protein content and lipid composition. We studied the growth and biochemical profile of Nannochloropsis 211/78 (CCAP) in optimized flat-plate photobioreactors. Eighteen cultivations were performed at two nutrient concentrations. The fatty acid, protein content and calorific values were analyzed after 8, 12 and 16 days. Neutral lipids were separated and the changes in fatty acids in triglycerides (TAGs) during nutrient depletion were recorded. The maximum cell density reached 4.7 g∙L-1 and the maximum productivity was 0.51 g∙L-1∙d-1. During nutrient-replete conditions, eicosapentaneoic acid (EPA) and total protein concentrations measured 4.2-4.9% and 50-55% of the dry mass, respectively. Nutrient starvation induced the accumulation of fatty acids up to 28.3% of the cell dry weight, largely due to the incorporation of C16:0 and C16:1n-7 fatty acyl chains into neutral lipids. During nutrient starvation the total EPA content did not detectibly change, but up to 37% was transferred from polar membrane lipids to the neutral lipid fraction.
微拟球藻是一种在工业上具有发展前景的微藻，由于其高产率、蛋白质含量和脂质组成，可用于培养替代营养源。我们研究了微拟球藻211/78（CCAP）在优化的平板光生物反应器中的生长和生化特性。在两种营养浓度下进行了18次培养。在第8、12和16天后分析脂肪酸、蛋白质含量和热值。分离中性脂质并记录营养耗尽期间甘油三酯（TAGs）中脂肪酸的变化。最大细胞密度达到4.7 g∙L-1，最大生产率为0.51 g∙L-1∙d-1。在营养充足的条件下，二十碳五烯酸（EPA）和总蛋白浓度分别占干质量的4.2-4.9%和50-55%。营养饥饿诱导脂肪酸积累至细胞干重的28.3%，这主要是由于C16:0和C16:1n-7脂肪酰链掺入中性脂质中。在营养饥饿期间，总EPA含量没有明显变化，但高达37%的EPA从极性膜脂转移到中性脂质部分。
