GENETIC ANALYSIS OF NONRIBOSOMAL PEPTIDE SYNTHESIS GENES (NRPSS) IN THE FRESH WATER ‎CYANOBACTERIAL OF THE LAVASAN LAKE

Background and Aim:Among the photosynthetic microorganisms, cyanobacteria are regarded as good candidates for ‎drug discovery, with applications in agriculture, industry and especially, in pharmaceuticals. To ‎date, the majority of bioactive metabolites isolated from cyanobacteria have either been ‎polyketides, non-ribosomal peptides, or a hybrid of the two. ‎Methods:In this study, efforts have been undertaken to investigate of ten cultured fresh water ‎cyanobacteria strains of the Lavasan Lake. These strains were identified based on the sequence ‎of ‎ 16 SrRNA gene and found that these strains belong to the Nostocaceae, Scytonemataceae and ‎Rivulariaceae. The antibiogram bioasyas were screened in phototrophic condition using a paper ‎disc method. The results showed that maximum antifungal activity was seen in Nostoc sp. Ft salt ‎and Scytonema sp. F 18 ‎ against Aspergillus niger and Fusarium sp. Nostoc sp. F 3 ‎ and Nostoc sp. ‎F 4 ‎ were the only strains that showed good activity against Bacillus cereus. Lastly, we conduct a ‎NRPS PCR, using molecular techniques, in order to sequence and phylogenetic analysis the ‎genes responsible for the production of secondary metabolites from ten cyanobacterial strains. ‎Moreover, Adenylation domain substrate specificity predictions for NRPS enzymes, the ‎signature sequence and the name of the compound, were made using NRPSpreditor 2 ‎. ‎Results:Sequence analysis indicates the enzymes encoded by these genes may be responsible for the ‎production of different secondary metabolites, such as antibiotics. The sequences of the genes ‎presented in this study have been deposited in GenBank. ‎Conclusion:The presented results prove that fresh water cyanobacterial of Iran are a promising source to yield ‎chemical and pharmaceutical interesting compounds.‎

کلیدواژه ها:

Peptide synthetase genes (NRPSs) ، Fresh water cyanobacterial ، Genetic analysis