Lipid Profiling of Methylococcus Capsulatus (Bath): Quantification and Characterization of Phospholipids, Glycolipids, and Free Fatty Acids By Rp-Hplc-Esi-Tof-Ms

Document Type


Degree Name

Master of Science (MS)



Date of Award

Summer 2013


The Prokaryotic bacteria, Methylococcus capsulatus Bath (MC), are methanotrophic organisms with a high acyl lipid synthesizing capacity (40% of dry biomass), particularly as a result of abiotic stresses such as nutrient deprivation, making them a promising feedstock for biodiesel production. For the lipid profiling of MC, the lipids are extracted by sonication with isoproponal and chloroform, followed by incubation, centrifugation and the addition of chloroform:methanol (1:1 v/v) before rotovap drying. The dried lipid sample was dissolved in water:methanol (3:2 v/v) and the lipids characterized using reversed phase-high performance liquid chromatography (RP-HPLC) and negative ion, electrospray ionization, time-of-flight mass spectrometry (ESI-TOF-MS). The phospholipids � phosphatidyl-glycerol (PG), phosphatidyl-inositol (PI), phosphatidyl-ethanolamine (PE), lysophosphatidyl-glycerol (LPG), lysophosphatidyl-inositol (LPI), lysophoaphatidyl-ethanolamine (LPE), glycolipids � sulfoquinovosyl-diacylglycerol (SQDG), sulfoquinovosyl-monoacylglycerol (SQMG) as well as the free fatty acids were identified using both the quadrupole auto settings and manual profile settings. The relative quantitative measurements of the lipids obtained from MC were compared to the lipids obtained from the micro algae Chlamydomonas reinhardtii (CR). Free fatty acids, SQDG, PG, PE, LPE, LPG, LPI, and SQMG were found in MC to be relatively in higher proportions when compared to CR. Fatty acids with 14, 15, 16, 18 and 20 carbon chains were found to be common for MC and CR.


Laurence Angel

Subject Categories

Chemistry | Physical Sciences and Mathematics