Fatty acid profiling of Chlamydomonas reinhardtii under nitrogen deprivation

• Published in: Bioresource technology Vol. 102; no. 3; pp. 3343 - 3351
• Main Authors: James, Gabriel O., Hocart, Charles H., Hillier, Warwick, Chen, Hancai, Kordbacheh, Farzaneh, Price, G. Dean, Djordjevic, Michael A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-02-2011; [New York, NY]: Elsevier Ltd; Elsevier
• Subjects: Biofuel; Biofuel production; Biological and medical sciences; Biotechnology; Chlamydomonas reinhardtii; Chlamydomonas reinhardtii - metabolism; Energy; Fatty acid; Fatty Acids - metabolism; Fundamental and applied biological sciences. Psychology; GC/MS; Industrial applications and implications. Economical aspects; Neutral lipid; Nitrogen - metabolism; Signal Transduction - physiology; Biofuel; Chlamydomonas reinhardtii; Fatty acid; GC/MS; Neutral lipid; Deprivation; Coupled method; Algae; Chlorophyceae; Nitrogen; Fatty acids; Gas chromatography; Chlorophyta; Mass spectrometry
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2010.11.051

The Chlamydomonas reinhardtii starch-less mutant, BAF-J5, was found to store lipids up to 65% of dry cell weight when grown photoheterotrophically and subjected to nitrogen starvation. Fourier transform infrared spectroscopy was used as a high-throughput method for semi-quantitative measurements of protein, carbohydrate and lipid content. The fatty acids of wild-type and starch mutants were identified and quantified by gas chromatography mass spectrometry. C. reinhardtii starch mutants, BAF-J5 and I7, produce significantly elevated levels of 16:0, 18:1Δ9, 18:2Δ9,12 and 18:3Δ9,12,15 fatty acids. Long-chain saturated, mono- and polyunsaturated fatty acids were found under nitrogen starvation. Oleosin-like and caleosin-like genes were identified in the C. reinhardtii genome. However, proteomic analysis of isolated lipid bodies only identified a key lipid droplet associated protein. This study shows it is possible to manipulate algal biosynthetic pathways to produce high levels of lipid that may be suitable for conversion to liquid fuels.