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

Energies

Jon Van Wagenen¹  Tyler W. Miller¹  Sam Hobbs¹  Paul Hook¹  Braden Crowe¹ 

[1] Pacific Northwest National Laboratory, 1529 W Sequim Bay Rd., Sequim, WA 98382, USA;

关键词: algae;    biofuels;    climate;    fatty acid;    Nannochloropsis salina;   

DOI  :  10.3390/en5030731

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.