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. 2020 Oct 10;25(20):4609.
doi: 10.3390/molecules25204609.

Improvement of Chemical Composition of Tisochrysis lutea Grown Mixotrophically under Nitrogen Depletion towards Biodiesel Production

Affiliations

Improvement of Chemical Composition of Tisochrysis lutea Grown Mixotrophically under Nitrogen Depletion towards Biodiesel Production

Adel W Almutairi. Molecules. .

Abstract

In the present study, the marine microalga Tisochrysis lutea was cultivated mixotrophically in F2 growth medium with sodium acetate as exogenous carbon source. The medium was composed of different concentrations of nitrogen to determine the impact of nitrogen depletion on cellular growth and chemical composition. Nitrogen depletion led to severely decreased growth and protein content. However, mild nitrogen depletion (0.22 mM NaNO3) led to maximum lipid yield. The fatty acid methyl ester profile also showed increased unsaturation as the nitrogen content decreased. Growth in nitrogen-free medium increased the proportions of mono- and poly-unsaturated fatty acids, while the proportion of saturated fatty acids decreased. Growth under all tested nitrogen levels showed undetectable fatty acids with ≥4 double bonds, indicating these fatty acids had oxidative stability. In addition, all tested nitrogen concentrations led to specific gravity, kinematic viscosity, iodine value, and cetane number that meet the standards for Europe and the U.S.A. However, growth in the presence of nitrogen deficiency enhanced the higher heating value of the resulting biodiesel, a clear advantage from the perspective of energy efficiency. Thus, mixotrophic cultivation of T. lutea with nitrogen limitation provides a promising approach to achieve high lipid productivity and production of high-quality biodiesel.

Keywords: biodiesel; carbohydrates; fatty acids; microalgae; pigments; protein.

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Conflict of interest statement

The author declares no conflict of interest.

Figures

Figure 1
Figure 1
The cellular dry weight of Tisochrysis lutea grown mixotrophically at different concentrations of NaNO3. * p < 0.05, ** p < 0.01, *** p < 0.001 with respect to the control (0.88 mM).
Figure 2
Figure 2
Crude protein (A), soluble protein (B), and true protein (C) content (as % dry weight (DW)) of Tisochrysis lutea grown mixotrophically in different concentrations of NaNO3. ** p < 0.01, *** p < 0.001, ns: not significant with respect to the control (0.88 mM).
Figure 3
Figure 3
Total carbohydrate content (as % DW) of Tisochrysis lutea grown mixotrophically in different concentrations of NaNO3. * p < 0.05, *** p < 0.001, ns: not significant with respect to the control (0.88 mM).
Figure 4
Figure 4
Contents of total chlorophyll (A) and carotenoids (B) in Tisochrysis lutea grown mixotrophically in different concentrations of NaNO3. ** p < 0.01, *** p < 0.001, ns: not significant with respect to the control (0.88 mM).
Figure 5
Figure 5
Lipid content (A) and volumetric lipid productivity (VLP) (B) of Tisochrysis lutea grown mixotrophically in different concentrations of NaNO3. * p < 0.05, ** p < 0.01, *** p < 0.001, ns: not significant with respect to the control (0.88 mM).

References

    1. Nayak M., Suh W.I., Chang Y.K., Lee B. Exploration of two-stage cultivation strategies using nitrogen starvation to maximize the lipid productivity in Chlorella sp. HS2. Bioresour. Technol. 2019;276:110–118. doi: 10.1016/j.biortech.2018.12.111. - DOI - PubMed
    1. Almutairi A.W. Effects of nitrogen and phosphorus limitations on fatty acid methyl esters and fuel properties of Dunaliella salina. Environ. Sci. Pollut. Res. 2020;27:32296–32303. doi: 10.1007/s11356-020-08531-8. - DOI - PubMed
    1. Abomohra A.E.-F., Elsayed M., Esakkimuthu S., El-Sheekh M., Hanelt D. Potential of fat, oil and grease (FOG) for biodiesel production: A critical review on the recent progress and future perspectives. Prog. Energy Combust. Sci. 2020;81:100868. doi: 10.1016/j.pecs.2020.100868. - DOI
    1. Yahya N.A., Suhaimi N., Kaha M., Hara H., Zakaria Z., Sugiura N., Othman N.A., Iwamoto K. Lipid production enhancement in tropically isolated microalgae by azide and its effect on fatty acid composition. J. Appl. Phycol. 2018;30:3063–3073. doi: 10.1007/s10811-018-1609-9. - DOI
    1. Yu S.J., Hu H., Zheng H., Wang Y.Q., Pan S.B., Zeng R.J. Effect of different phosphorus concentrations on biodiesel production from Isochrysis zhangjiangensis under nitrogen sufficiency or deprivation condition. Appl. Microbiol. Biotechnol. 2019;103:5051–5059. doi: 10.1007/s00253-019-09814-y. - DOI - PubMed

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