Rapid separation of microbial lipids using solid phase extraction columns

Abstract

A method was developed to rapidly separate lipid classes commonly found in microorganisms. The method is based on the use of aminopropyl solid phase extraction columns to separate polyhydroxyalkanoates (PHA), phospholipids, sterols, triglycerides, diglycerides, monoglycerides, and steryl esters. Recoveries of all lipid classes, with the exception of PHA and sterols, ranged from 91% to greater than 99%. PHA were recovered at 69% of the standard, and sterols from 82–84% of the standard. When applied to the analysis of lipids extracted from the cyanobacterium Spirulina platensis, the method afforded excellent recovery and separation of phospholipids and diglycerides including saturated, monounsaturated and polyunsaturated fatty acids. The S. platensis lipids also contained hydrocarbons and phytol recovered in the steryl ester and diglyceride fractions, respectively. This method provided a high yield, specific and rapid separation of microbial lipids with little contamination from other lipid groups, and will be useful for the characterization of microbial communities in environmental samples.