Detection and Relation of Polyketide Synthase (PKSs) Genes With Antimicrobial Activity in Terrestrial Cyanobacteria of Lavasan

Background and Aims: Cyanobacteria are considered as favorable source for new pharmaceutical compounds. To date, the majority of bioactive metabolites isolated from cyanobacteria are either polyketides (PKSs) or non-ribosomal peptides. Despite of several worldwide studies on prevalence of PKSs, none of them included the terrestrial cyanobacteria of the Lavasan. Therefore, this study aimed to detectthe PKS genes and correlation of the presence of these genes with antimicrobial compounds synthesis. Materials and Methods: Morphological and molecular identification of the terrestrial strains was performed after culture and purification. Amplification of polyketide synthase and phylogenetic trees were used for ‎phylogenetic analysis. Nucleotide and protein sequences were deposited in GenBank. Lastly, to show the correlation of this gene with antimicrobial compounds synthesis, antibiogram bioassay was used. Results: Phylogentic analysis revealed that most of the identified 16SrRNA genes and PKS domains had more than 90% similarity to their closest matches in the Gen-Bank. In addition, antibiogram assessment showedthe different pattern of inhibition, indicating the involvement of variety antimicrobial substances. Conclusions: According to the results of this sudy, it seems the antibiogram bioassay and molecular detection of polyketide synthase genes are useful techniques for the assessment of productive species of natural products and the possible role of polyketide synthase enzyme complexes in the biosynthesis of biologically active compounds.