Quantification and characterization of glycolipids and phospholipids of Chlamydomonas reinhardtii by HPLC-ESI-TOF-MS.

摘要

The eukaryotic green algae, Chlamydomonas reinhardtii (CR) has a high lipid synthesizing capacity, particularly as a result of abiotic stresses such as nutrient deprivation or elevated light exposure, giving CR the potential for being a source of oils for the production of biodiesel. In this research, the lipids of CR were extracted by utilizing sonication with isopropanol and chloroform, followed by 12hr incubation at 48°C, centrifugation and addition of 1:1 methanol:choloroform. The dried sample was finally extracted using water:methanol 3:2. Characterization of the lipids of CR was achieved by high performance liquid chromatography (HPLC) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). The quantitative measurements of phosphatidylglycerol, phosphatidylinositol, sulfoquinovosyldiacylglycerol, and free fatty acids were compared to those obtained from the algae Nannochloropsis oculata (NO) by He et al. Sulfoquinovosyldiacylglycerol was determined for CR to have the highest relative proportion which agreed with the previous NO analysis. However, the relative proportion of phosphatidylglycerol and phosphatidylinositol was higher for CR than NO. Fatty acids with 16 carbon and 18 carbon chains were found to be common for CR and NO. Free fatty acids were found in CR to be in relative higher proportions when compared to the lipids in CR and NO. The quantitative measurements of isoforms of sulfoquinovosyldiacylglycerol and phosphatidylglycerol were also compared to those obtained from Stephanodiscus sp by Xu et al.