|Acclimation of chemical composition and photosynthesis of nannochloropsis sp. during nitrogen limitation|
Labudzik, I. (2019). Acclimation of chemical composition and photosynthesis of nannochloropsis sp. during nitrogen limitation
. Thesis. NIOZ Royal Netherlands Institute for Sea Research: Yerseke. 41 pp.
The production of algal biomass with a known taste, composition and nutritious value was initially studied to increase the food production worldwide. The addition of algal growth to the traditional food production can overcome the problem of food deficiency within 25 years. Before it can be applied on bigger scale the process of growing and harvesting algal biomass needs to be optimized. During this study the focus lies on the production of algal biomass in different growing situations and their adaptation to the situations. Nitrogen limitation is known to induce lipid accumulation in Nannochloropsis sp. cells, mainly the lipid triacylglycerol is produced through the acetyl-CoA-independent pathway (Xiao, Zhang, Cui, Feng, & Cui, 2013). To analyze the effect of nitrogen limitation the cells were grown in continuous cultures with a limited amount nitrogen in the growth medium. The differences in chemical composition and photosynthetic performances of the cells were followed during the limitation by chemical analysis and spectrophotometric measurements. We can conclude that the limitation of nitrogen induced the accumulation of lipids in the cells during nitrogen limitation, and the carbohydrates and protein content in the cells will decrease due to a deficiency in amino acids. The photosynthetic performances of the cells are not significant affected during nitrogen limitation in this study, only the amount of the chlorophyll a is lowered during the limitation phase. Our research suggests that the production of lipid rich algal biomass can be increased by growing Nannochloropsis sp. in a nitrogen limited environment.