DETECTION OF THE POLYKETIDE SYNTHASE (PKSS) GENES WITH ANTIMICROBIAL ACTIVITY IN SOIL ‎CYANOBACTERIA OF THE LAVASAN

Background and Aim:Cyanobacteria produce a tremendous variety of secondary bioactive metabolites. Many of these ‎compounds have biological activity. ‎Methods:In the current study, we focused on the detection of polyketide synthase (PKSs) genes in seven ‎soil cyanobacteria strains of the Lavasan. Total genomic DNA was extracted from exponential ‎phase cultures. The sequences of the 16s rRNA region were determined. Moreover amplification ‎of polyketide synthase was achieved. Results showed amplification of the appropriate ~700 bp ‎for peptide synthetase. Also, analyses of antibiogram bioassay were screened. In vitro ‎antibacterial activities of organic extracts of studied strains were evaluated against Gram-positive ‎bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). Dried extracts ‎and supernatants were dissolved in methanol and antimicrobial activity was determined by the ‎disc method. ‎Results:The extract of Nostoc sp. Ft11 showed more potent activity against Staphylococcus aureus and ‎no inhibitory effect was found against Escherichia coli.‎Conclusion:According to these results, it is concluded that the antibiogram bioassay and molecular detection ‎of polyketide synthase (PKSs) genes in the soil cyanobacterial strains of Iran may be useful ‎techniques for the assessment of natural product -producing species. ‎

Keywords:

Polyketide synthase (PKSs) , Soil cyanobacteria , Antimicrobial activity