General Microbiology Laboratory, USA
Tropical marine cyanobacteria produce an array of biologically active secondary metabolites. Despite of, the taxonomic classification of cyanobacteria is not yet resolved and it is constantly under revision. Modern taxonomic approach composed of morphological and phylogenetic analysis. However, there are limitations in terms of the morphological approach. The current study focused on whether the secondary metabolites produced by cyanobacteria is species specific and whether these chemicals can be used to foster the taxonomic relationship between the phylogenetically distinct various marine cyanobacterial species. We also aimed to develop a rapid chemotaxonomic tool for the identification of cyanobacteria on the basis of its major secondary metabolites. We are hypothesizing that each species would always produce the major chemotype irrespective of the geographical locations and these will be the major chemical markers of those species. To examine this, we compared the secondary metabolite compositions and 16S rRNA sequences among several collections of cyanobacteria from South Florida, the Caribbean, and Hawaii region. The chemical profiling was performed by using ESI-LC-MS to screen for secondary metabolites. MALDI-TOF was used for rapid identification of the metabolites. We found out that the several collections of cyanobacterial species always produce the major chemotype irrespective of geographical locations. We also showed that the MALDI-TOF can contribute to rapid and accurate identification of the core chemotype and hence more accurate taxonomies.