The fatty acid composition of bacteria is widely used as a chemotaxonomic standard in polyphasic taxonomy. The primary source of fatty acids in bacterial cells is the membrane, which contains the majority of the > 300 fatty acids and related compounds already found in bacteria. When analyzing the fatty acid composition, not only the presence or absence but also the relative concentration of each compound is taken into account. To allow qualitative and quantitative analysis in a reproducible way, standardized culturing conditions are needed to obtain stable fatty acid profiles.
At BCCM/LMG, determination of whole-cell fatty acid composition by means of FAME (Fatty Acid Methyl Ester) analysis is offered as a customer service.
Analysis is performed gas chromatographically using an Agilent Technologies 6890N gas chromatograph (Santa Clara, CA USA). Cultivation, harvesting, extraction and analysis of fatty acids are performed conform to the recommendations of the commercial identification system MIDI (Microbial Identification System, Inc., Delaware U.S.A.). Different peak naming tables for specific bacterial groups can be used to identify the obtained fatty acids.
The service report includes information on the cultivation conditions, technical specifications and the MIDI report sheet with the fatty acid composition. On request, clustering of multiple profiles to delineate groups with common fatty acid compositions can be performed using the BioNumerics v7.0 software program.
Sasser, M. (1990). Identification of bacteria by gas chromatography of cellular fatty acids. MIDI Technical Note 101. Microbial ID Inc., Newark, DE, USA.
Mergaert, J., Verhelst, A., Cnockaert, M.C., Tan, T.L., Swings, J. (2001). Characterization of facultative oligotrophic bacteria from polar seas by analysis of their fatty acids and 16S rDNA sequences. Syst Appl Microbiol 24: 98-107. doi:10.1078/0723-2020-00012