Microalgal cultivation systems for energy production are not yet economically viable due to the low yield of lipids and biomass. In this study, we propose a chemical approach, using exogenous bioactive molecules for improving algal growth, lipid content and the production of high-value alpha-linolenic acid (ALA), using Chlorella protothecoides as a model. Based on our findings, among the cytokinin and auxin classes, Kinetin increased the biosynthesis of ALA by 26.5% at 1 ppm concentration, and indole-3-butyric acid at 2 ppm improved the biomass and lipid productivity up to 29.15 ± 2.02 g m− 2 day− 1, and 6.69 ± 0.56 g m− 2 day− 1, respectively. Methyl jasmonate as a stress-related phytohormone also showed a positive stimulatory effect on growth of C. protothecoides, and the biomass productivity was increased up to 25.26 ± 1.48 g m− 2 day− 1 at the concentration of 5 ppm (lipid content: 219.66 ± 13.20 mg g− 1 dw; lipid productivity: 5.61 ± 0.25 g m− 2 day− 1; ALA: 0.81 ± 0.16 g m− 2 day− 1). A difference in the composition of fatty acids, due to the type and concentrations of stress-related phytohormones was observed, and under the influence of stress-related phytohormones, the biosynthesis of saturated fatty acids increased, and polyunsaturated fatty acids decreased in C. protothecoides. Butylated hydroxyanisole, at a concentration of 0.05 ppm, increased the ALA content by 60.5%. Our study shows that the proposed bioactive molecules could increase the biomass productivity of C. protothecoides at a lower cost compared to the use of acetate as a carbon source.
Bibliographical noteFunding Information:
The financial support and experimental facilities provided by the School of Engineering and Sciences, Emerging Technologies and Molecular Nutrition Research Group from Tecnologico de Monterrey, Mexico, and the CONACYT scholarship (No. 446209) to E.M-A are thankfully acknowledged.
© 2017 Elsevier B.V.
Copyright 2017 Elsevier B.V., All rights reserved.
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science