BENDJEMANA KATIA2024-02-272024-02-272022-01-04http://dspace.univ-khenchela.dz:4000/handle/123456789/2147The cyanobacteria management in water bodies requires a deep knowledge of the community composition. Considering the reliable and thorough information provided by the polyphasic approach in cyanobacteria taxonomy, here we assess the cyanobacterial community structure of the Chefa reservoir from Algeria. Cyanobacteria were identifed on the basis of morphological traits and next-generation sequencing (NGS); toxins-related genes were localized in addition to the identifcation of toxins; temperature and nutrient level of water samples were also determined. The polyphasic approach was essential for cyanobacteria investigation; 28 genera were identifed through 16S rRNA metabarcoding with the dominance of taxa from Microcystis (34.2%), Aphanizomenon (20.1%), and Planktothrix (20.0%), and morphological analysis revealed the association in this water body of fve species within the genus Microcystis: M. aeruginosa, M. novacekii, M. panniformis, M. ichthyoblabe, and M. fos-aquae. The presence of mcyE genotypes was detected; moreover, HPLC–PDA and LC–ESI–MS/ MS revealed the production of microcystin-LR. Results obtained in our study are very important since this ecosystem is used for water supply and irrigation; as a consequence, a good water management plan is essential.enArticle