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. Show
This is a preview of subscription content, access via your institution. Access optionsBuy single articleInstant access to the full article PDF. 39,95 € Price includes VAT (Australia) Rent this article via DeepDyve. Learn more about Institutional subscriptions Fig. 1  Fig. 2 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 CAS Google Scholar Brown MR, Jeffrey SW, Volkman JK, Dunstan GA (1997) Nutritional properties of microalgae for mariculture. Aquaculture 151:315–331 Article CAS Google Scholar 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 Article CAS Google Scholar 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 Article CAS Google Scholar Guschina I, Harwood J (2006) Lipids and lipid metabolism in eukaryotic algae. Prog Lipid Res 45:160–186 Article PubMed CAS Google Scholar 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 Chapter Google Scholar Riebesell U, Wolf-Gladrow DA, Smetacek V (1993) Carbon dioxide limitation of marine phytoplankton growth rates. Nature 361:249–251 Article CAS Google Scholar 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 Article CAS Google Scholar Smith F, Raven JA (1979) Intracellular pH and its regulation. Ann Rev Plant Physiol 30:289–311 Article CAS Google Scholar Williams PJB, Laurens LML (2010) Microalgae as biodiesel & biomass feedstocks: Review & analysis of the biochemistry, energetics & economics. Energ Environ Sci 3:554–590 Google Scholar Download references AcknowledgmentsThis 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 informationAuthors and Affiliations
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Corresponding authorCorrespondence to Kristian Spilling. Electronic supplementary materialBelow is the link to the electronic supplementary material. ESM 1(DOC 28 kb) ESM 2(DOC 27 kb) Rights and permissionsReprints and Permissions About this articleCite this articleSpilling, 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 Do lipids have a pH?The pH value is identified as an essential determinant for the lipid synthesis in the stratum corneum (SC). The activity of the enzymes that catalyse the transformation of lipid precursors into ceramides, free fatty acids or cholesterol highly depends on pH value.
Is lipid acidic or alkaline?Structure of lipids
All lipids do however contain at least one hydrocarbon chain (i.e. a chain of carbon and hydrogen atoms) with an acidic end.
What is the pH effect of lipids?Membrane lipids are directly affected by pH, due to their acido-basic properties. pH change can induce lipid vesicle migration and global deformation. pH change can cause polarization in phase-separated membrane of GUVs. Localized pH heterogeneities can induce local dynamical membrane deformations.
What is the pH value of fat?Since fat globules carry a negative charge normally (Mommsen (5)), with its isoelectric point at pH 4.3 (North and Sommer.
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What is the pH of lipids
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