The phytohormone abscisic acid increases triacylglycerol content in the green microalga Chlorella saccharophila (Chlorophyta)

• Published in: Algae (Korean Phycological Society) Vol. 31; no. 3; pp. 267 - 276
• Main Authors: Contreras-Pool, Patricia Yolanda, Peraza-Echeverria, Santy, Ku-González, Ángela Francisca, Herrera-Valencia, Virginia Aurora
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Phycology (Han'gug Joryu Haghoe) 01.09.2016; 한국조류학회I
• Subjects: Abscisic acid; Algae; Biodiesel fuels; Biomass; Chlorella saccharophila; Chlorophyta; Fatty acids; Lipids; Nitrogen; 생물학
• ISSN: 1226-2617; 2093-0860
• DOI: 10.4490/algae.2016.31.9.3

Microalgae are currently a very promising source of biomass and triacylglycerol (TAG) for biofuels. In a previous study, we identified Chlorella saccharophila as a suitable source of oil for biodiesel production because it showed high biomass and lipid content with an appropriate fatty acid methyl esters profile. To improve the TAG accumulation in C. saccharophila, in this study we evaluated the effect of abscisic acid (ABA) addition on cell concentration, lipid content and TAG production in this microalga. First, we evaluated the effects of four ABA concentrations (1, 4, 10, and 20 μM) added at the beginning of a single-stage cultivation strategy, and found that all concentrations tested significantly increased cell concentration and TAG content in C. saccharophila. We then evaluated the addition of 1 μM ABA during the second stage of a two-stage cultivation strategy and compared it with a nitrogen deficiency treatment (ND) and a combination of ND and ABA (ND + ABA). Although ABA alone significantly increased lipid and TAG contents compared with the control, ND showed significantly higher TAG content, and ND + ABA showed the highest TAG content. When comparing the results of both strategies, we found a superior response in terms of TAG accumulation with the addition of 1 μM ABA at the beginning of a single-stage cultivation system. This strategy is a simple and effective way to improve the TAG content in C. saccharophila and probably other microalgae as a feedstock for biodiesel production.