The fatty acid composition of the strains is obtained by automated analysis of fatty acid methyl ester (FAME) by gas chromatography.

Strains and bacterial isolates recorded in MIDI libraries can be identified and characterized using the MIDI system (Sherlock Microbial Identification System).

Because the fatty acid profile closely depends on the culture conditions used, it is essential to send active culture strains and specify the growth conditions required for the determination of fatty acids. For fastidious strains or specific requirements, cell mass that has been frozen and collected following relevant specifications may be sent.

Necessary material

Active culture of the strain (Petri dish or slant).

For fastidious strains or specific requirements, 40 mg of frozen bacterial biomass.

Methodology

For extraction of cellular fatty acids we follow the protocol recommended by MIDI Microbial Identification System (Sasser, 1990). Cellular fatty acid content is separated on an Agilent 6850 gas chromatograph, and subsequently analysed with the MIDI Microbial Identification System, using TSBA6 or CLIN6 (MIDI, 2008) methods.

Bibliography

MIDI (2008). Sherlock Microbial Identification System Operating Manual, version 6.1. Newark, DE: MIDI Inc.

Sasser, M. (1990). Identification of bacteria by gas chromatography of cellular fatty acids, MIDI Technical Note 101. Newark: DE: MIDI Inc