Effects of Light and Temperature on Fatty Acid Production in Nannochloropsis Salina

Abstract

Accurate prediction of algal biofuel yield will require empirical determination of physiological responses to the environment, particularly light and temperature. One strain of interest, Nannochloropsis salina, was subjected to ranges of light intensity (5-850 μmol m −2 s −1 ) and temperature (13-40 °C) and its exponential growth rate, total fatty acids (TFA) and fatty acid composition were measured. The maximum acclimated growth rate was 1.3 day −1 at 23 °C and 250 μmol m −2 s −1 . Fatty acids were detected by gas chromatography with flame ionization detection (GC-FID) after transesterification to corresponding fatty acid methyl esters (FAMEs). A sharp increase in TFA containing elevated palmitic acid (C16:0) and palmitoleic acid (C16:1) during exponential growth at high light was observed, indicating likely triacylglycerol accumulation due to photo-oxidative stress. Lower light resulted in increases in the relative abundance of unsaturated fatty acids; in thin cultures, increases were observed in palmitoleic and eicosapentaenoic acids (C20:5ω3). As cultures aged and the effective light intensity per cell converged to very low levels, fatty acid profiles became more similar and there was a notable increase of oleic acid (C18:1ω9). The amount of unsaturated fatty acids was inversely proportional to temperature, demonstrating physiological adaptations to increase membrane fluidity. These data will improve prediction of fatty acid characteristics and yields relevant to biofuel production. OPEN ACCESSEnergies 2012, 5 732

Global evaluation of biofuel potential from microalgae

“…Nannochloropsis is a promising strain for biofuel production because of its characteristically high lipid content (9,21,32). The model captures growth through carbon uptake, assuming a 50% carbon content (2,33), and includes photosynthetic rate (P c ), respiration rate (rR c ), and biosynthetic energy required for nitrogen uptake ðΨÞ to calculate the growth rate (μ):…”

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Response to oxidative stress induced by high light and carbon dioxide (CO2) in the biodiesel producer model Nannochloropsis salina (Ochrophyta, Eustigmatales)

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The Effects of Transesterification and Blending on the Fatty Acid Profiles of Vegetable Oils

“…During the transesterification of algae, Wagenen, et al, [25] reported a sharp increase in total fatty acid containing elevated palmitic and palmitoleic during exponential growth at high light intensity but with low light intensity, an increase in the relative abundance of unsaturated fatty acid was noted. They also noted that fatty acid increased inversely with temperature.…”