Biosynthesis of high yield fatty acids from Chlorella vulgaris NIES-227 under nitrogen starvation stress during heterotrophic cultivation. (15th September 2015)

• Record Type: Journal Article
• Authors: Shen, Xiao-Fei; Chu, Fei-Fei; Lam, Paul K.S.; Zeng, Raymond J.
• Is Part Of: Water research. Volume 81(2015)
• Page Start: 294
• Page End: 300
• Publication Date: 2015-09-15
• Subjects: Microalgae -- Nitrogen starvation -- Heterotrophic cultivation -- Fatty acid content -- Fatty acid yield -- Glucose; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2015.06.003
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: In this study the heterotrophic cultivation of Chlorella vulgaris NIES-227 fed with glucose was investigated systematically using six media types; combinations of nitrogen repletion/depletion and phosphorus repletion/limitation/depletion. It was found that a high yield of fatty acids (0.88 of fed glucose-COD) and a high content of fatty acid methyl esters (FAMEs) (89% of dry weight) were obtained under nitrogen starved conditions. To our knowledge it is the first report on such high COD conversion yield and FAME content in microalgae. The dominant fatty acid (>50%) was methyl oleate (C18:1), a desirable component for biodiesel synthesis. FAME content under nitrogen starved conditions was significantly higher than under nitrogen sufficient conditions, while phosphorus had no significant influence, indicating that nitrogen starvation was the real "fatty acids trigger" in heterotrophic cultivation. These findings could simplify the downstream extraction process, such as the extrusion of oil from soybeans, and could reduce operating costs by improving the fatty acid yield from waste COD. Graphical abstract: Highlights: The yield of fatty acids from glucose (COD based) reached as high as 0.88. An extremely high content of fatty acids (89% of dry weight) was obtained. Nitrogen starvation was the real "fatty acids trigger" in heterotrophic cultivation. Potential to make the downstream lipid extraction process more economical.