chemotaxonomic

Chemotaxonomy, or chemotaxonomic analysis, is a method in biological taxonomy that classifies and identifies organisms based on the chemical constituents they produce or incorporate. The approach uses chemical traits that are relatively conserved within taxa or diagnostic for particular groups, including cell wall composition and structure, membrane lipids, quinones, fatty acid patterns, pigments, and, in plants and fungi, secondary metabolites such as alkaloids, terpenoids, and flavonoids.

In microbiology, chemotaxonomy often relies on fatty acid methyl ester (FAME) profiling, isoprenoid quinone typing, and polar lipid analysis to distinguish species and genera. It is frequently integrated with molecular data, such as 16S rRNA gene sequences, DNA-DNA hybridization, or genome-based phylogenies, to produce a more robust taxonomy.

Chemotaxonomic data can complement morphology, physiology, and genetic information, especially when genetic data alone are insufficient to resolve relationships or when rapid identification is needed. However, chemical traits can be influenced by growth conditions, nutrient availability, and environmental factors, and different lineages can converge on similar chemical profiles. Therefore, chemotaxonomy is typically used as part of a polyphasic approach.

Applications include systematics and identification of bacteria, archaea, fungi, and plants, the description of new taxa, and biotechnological or ecological studies that rely on chemical diversity as a taxonomic signal. Related techniques include FAME profiling, quinone analysis, and metabolite profiling.