Isolation and Characterization of Cyanobacterial Community Including a Microcystin-Producing Nostoc sp. Strain in the Nile River, Egypt

摘要

The combined use of morphological identification and phylogenetic characterization employing primers that target the 16S rDNA region led to the identification of ten isolates belonging to eight cyanobacterial genera in the Nile River. 16S-23S ITS region was amplified to confirm two isolates to be affiliated to genus Nostoc. Using MALDI-TOF/MS, we detected the production of the hepatotoxic demethylated MC-LR by one isolate that clustered together with the genus Nostoc. Protein phosphatase inhibition assay has confirmed toxicity. Our results add to the rising importance of Nostoc as a hepatotoxin-producing cyanobacterium. Furthermore, our results stress that water municipalities in the studied region need to assess the potential threat of toxic cyanobacteria that may pose to human health and economy.