Fatty Acids Analysis of Photosynthetic Sulfur Bacteria by Gas Chromatography

The fatty acid profile of bacteria has been extensively studied for taxonomic classification purposes, as bacteria in general contain particular and rare fatty acids, compared with animal and plant tissues (Purcaro et al., 2010). Lipids and fatty acid composition are quite useful for characterization of different species and groups of photosynthetic bacteria. Fatty acids can be identified by gas chromatography using standard methods (Imhoff & Caumette, 2004) because physical and chemical factors (e.g., illumination) influence bacterial fatty acid composition, culture conditions, and the culture media used for bacterial growth. Fatty acid analysis as a chemotaxonomic tool has been applied in heterotrophic bacteria, but its use in photosynthetic sulfur bacteria it is very limited. Actually, most studies on photosynthetic purple and green sulfur bacteria fatty acid composition have been done with relatively few genera and have often given information of the major fatty acids.