Molecular Diagnosis and Detection of the HEP Gene in Some Cyanobacterial Species Isolated from the Local Environment

Background: Cyanobacteria are microorganisms that lack a true nucleus inside their cells and are found in various environments around the world. They exist in both wild and aquatic environments and can tolerate harsh conditions such as high temperature, salinity, and low light intensity.This study aimed to verify and detect the presence of the HEP gene, which is responsible for the production of hepatic toxins, in several species of local isolates of filamentous cyanobacteria. Methodology: Samples of cyanobacteria were collected from different environmental sources and cultured in BG11 medium. DNA was extracted from the isolates, and the target HEP gene along with the diagnostic 16S rRNA gene was amplified using the Polymerase Chain Reaction (PCR) technique. The PCR products were analyzed by agarose gel electrophoresis to determine the presence or absence of the target genes. The analysis of the 16S rRNA gene sequences revealed a high genetic similarity among species within the same genus and an average similarity among species belonging to different families. Results: The results showed that most of the cyanobacterial isolates carried the HEP gene, including Oscillatoria nigro-viridis, Limnospira fusiformis, Wollea saccata, Chroococcus sp., and Spirulina platensis, while Lyngbya aestuarii, Anabaena lutea, and Oscillatoria sp. did not possess this gene. Conclusions: These findings indicate that the ability to produce hepatic toxins is species-dependent and varies even among cyanobacteria belonging to the same genus. The study highlights the importance of monitoring cyanobacterial species in different environments due to their potential to produce harmful toxins.