Abstract
We tested the hypothesis that increased pH reduces the amount of structural lipids. To do this, we used three different diatoms (Phaeodactylum tricornutum CCAP strain, P. tricornutum TV strain and Amphiprora sp). We tested the effect of rapid increase from pH 7.5 to 10 by adding NaOH. The total lipid content was reduced by 13, 36 and 47 % in the P. tricornutum CCAP strain, TV strain and Amphiprora sp., respectively, 1 h after increasing the pH. The P. tricornutum CCAP strain was used for further testing the effect of pH on the lipid content during active growth. This strain was cultivated at pH 7.5 and 10, and the pH was regulated by the CO2 inflow. The growth rate was similar (0.3 day−1) in both pH treatments, but the lipid content in the pH 10 treatment was on average 28 % lower than in the pH 7.5 treatment. Our data support the hypothesis that structural lipids are reduced when pH increases to high levels. The results suggest that regulating the pH during algae cultivation could be used to refine the lipid composition in the harvested algal biomass.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Badger MR, Andrews TJ, Whitney SM, Ludwig M, Yellowlees DC, Leggat W, Price GD (1998) The diversity and coevolution of Rubisco, plastids, pyrenoids, and chloroplast-based CO2-concentrating mechanisms in algae. Can J Bot 76:1052–1071
Brown MR, Jeffrey SW, Volkman JK, Dunstan GA (1997) Nutritional properties of microalgae for mariculture. Aquaculture 151:315–331
Gardner R, Peters P, Peyton B, Cooksey K (2011) Medium pH and nitrate concentration effects on accumulation of triacylglycerol in two members of the Chlorophyta. J Appl Phycol 23:1005–1016
Guckert J, Cooksey K (1990) Triglyceride accumulation and fatty acid profile changes in Chlorella (Chlorophyta) during high pH-induced cell cycle inhibition. J Phycol 26:72–79
Guschina I, Harwood J (2006) Lipids and lipid metabolism in eukaryotic algae. Prog Lipid Res 45:160–186
Guschina I, Harwood J (2009) Algal lipids and effect of the environment on their biochemistry. In: Arts M, Brett M, Kainz M (eds) Lipids in aquatic ecosystems. Springer, New York, pp 1–24
Riebesell U, Wolf-Gladrow DA, Smetacek V (1993) Carbon dioxide limitation of marine phytoplankton growth rates. Nature 361:249–251
Santos AM, Janssen M, Lamers PP, Evers WAC, Wijffels RH (2012) Growth of oil accumulating microalga Neochloris oleoabundans under alkaline-saline conditions. Bioresource Technol 104:593–599
Smith F, Raven JA (1979) Intracellular pH and its regulation. Ann Rev Plant Physiol 30:289–311
Williams PJB, Laurens LML (2010) Microalgae as biodiesel & biomass feedstocks: Review & analysis of the biochemistry, energetics & economics. Energ Environ Sci 3:554–590
Acknowledgments
This study was funded by the Academy of Finland Research Programme “Sustainable Energy” (SusEn), the Nordic Energy Research Programme “N-INNER” and the Technology Development Fund in Iceland (grant no. 101253011). Additionally, a mobility grant was given to KS from the Nordic Marine Academy. We would also like to thank Hannes Lárus Jóhannsson, Sigrún Helgadóttir, Airi Hyrkäs and Jaana Rikkinen for their excellent technical assistance. The Amphiprora sp was isolated by Sigurbjörn Einarsson.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Spilling, K., Brynjólfsdóttir, Á., Enss, D. et al. The effect of high pH on structural lipids in diatoms. J Appl Phycol 25, 1435–1439 (2013). https://doi.org/10.1007/s10811-012-9971-5
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10811-012-9971-5