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Advisor(s)
Abstract(s)
The current focus of algae biotechnology is the production of high-value lipids, and its improvement by 
employing abiotic perturbations such as nitrogen-induced changes. In the present study, the growth dynamics, 
nitrogen uptake, pigments, and lipid composition of Chlorellla stigmatophora and Hemiselmis cf. andersenii were 
studied, in response to low (LN), medium (MN) and high (HN) nitrogen supplementations. Both microalgae 
responded to increased nitrogen levels by increasing their nitrogen uptake rate and pigment content. However, 
for lipid accumulation, C. stigmatophora presented a different pattern (LN: 16.56% > MN: 11.51% > HN: 10.95%) 
to that of H. cf. andersenii (MN: 15.37% > HN: 13.06% > LN: 6.71%). Untargeted gas chromatography–mass 
spectrometry analysis allowed the visualization of the biochemical diversity of C. stigmatophora and H. cf. 
andersenii, as well as differences in lipid regulation upon nitrogen-induced changes among species. For instance, 
glycosyl sterols were only detected for C. stigmatophora samples grown under MN and HN conditions. Moreover, 
lipid analysis of H. cf. andersenii, before and after alkaline hydrolysis, suggests that wax esters play a key role in 
the response of this microalga to high nitrogen levels. The cultivation of H. cf. andersenii at MN and HN was 
shown to be ideal for providing a rich source of ω3 and polyunsaturated fatty acids for nutraceutical purposes. 
The hierarchical cluster analysis showed the differential intra- and interspecific effects of nitrogen on lipid 
composition. The diverse ways by which both microalgae responded to nitrogen-induced changes highlighted the 
influence of phylogeny on the carbon flux through metabolic networks, and accumulation.
Description
Keywords
 Nitrogen supplementation   Hemiselmis cf. andersenii   Chlorella stigmatophora   Lipidome analysis   Nutraceutical lipids   .   Faculdade de Ciências Exatas e da Engenharia 
Pedagogical Context
Citation
Fernandes, T., Ferreira, A., & Cordeiro, N. (2021). Comparative lipidomic analysis of Chlorella stigmatophora and Hemiselmis cf. andersenii in response to nitrogen-induced changes. Algal Research, 58, 102417.
Publisher
Elsevier
