Analysis of Soil Lipids for Studies of Microbial Communities

Abstract

Lipids are a heterogenic group of natural chemical compounds, having in common low solubility in polar solvents and high in nonpolarsolvents. This definition includes steroids, carotenoids, terpenes and biliar acids. But also non-lipid substances like hydrocarbons.Chemical structure and biological functions of these compounds can be quite different. In a more restrictive definition, lipids are consideredas fatty acids and their derivatives (amides and esters), together with compounds related through biosynthesis paths of biologicalfunction.The most abundant lipid are the fatty acids linked by ester links to an alcohol (like glycerol), including acyl-glycerols (often calledneutral lipids) and polar lipids, where one fatty acid is replaced by a sugar and a phosphate group (phospholipids).Neutral lipids are important systems for storing energy in eukaryote organisms, while phospholipids are structural lipids in the cellmembrane of every living being, constituting a double layer that allows polar molecules and ions passing through the cell.