Related Experiment Video
Updated: Jun 12, 2026

Identification of Fatty Acids in Bacillus cereus
Published on: December 5, 2016
Classification of bacteria by simultaneous methylation-solid phase microextraction and gas chromatography/mass
1Clippinger Laboratories, Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701-2979, USA.
Abstract:
Direct methylation and solid-phase microextraction (SPME) were used as a sample preparation technique for classification of bacteria based on fatty acid methyl ester (FAME) profiles. Methanolic tetramethylammonium hydroxide was applied as a dual-function reagent to saponify and derivatize whole-cell bacterial fatty acids into FAMEs in one step, and SPME was used to extract the bacterial FAMEs from the headspace. Compared with traditional alkaline saponification and sample preparation using liquid-liquid extraction, the method presented in this work avoids using comparatively large amounts of inorganic and organic solvents and greatly decreases the sample preparation time as well. Characteristic gas chromatography/mass spectrometry (GC/MS) of FAME profiles was achieved for six bacterial species. The difference between Gram-positive and Gram-negative bacteria was clearly visualized with the application of principal component analysis of the GC/MS data of bacterial FAMEs. A cross-validation study using ten bootstrap Latin partitions and the fuzzy rule building expert system demonstrated 87 +/- 3% correct classification efficiency.
More Related Videos
Related Concept Videos
Methods of Classification and Identification
Modern Molecular Taxonomy
Rapid Identification of Pathogens
Applications of Molecular Taxonomy
Microbial Classification System
Differential Staining Technique

