Research Article| April 13 2016 Occurrence of toxic cyanobacteria and microcystin toxin in domestic water storage reservoirs, Egypt Zakaria A. Mohamed; Zakaria A. Mohamed 1Department of Botany and Microbiology, Faculty of Science, Sohag University, Sohag, Egypt E-mail: mzakaria_99@yahoo.com Search for other works by this author on: This Site PubMed Google Scholar Mohamed Ali Deyab; Mohamed Ali Deyab 2Botany Department, Faculty of Science, Damietta University, Damietta, Egypt Search for other works by this author on: This Site PubMed Google Scholar Mohamed I. Abou-Dobara; Mohamed I. Abou-Dobara 2Botany Department, Faculty of Science, Damietta University, Damietta, Egypt Search for other works by this author on: This Site PubMed Google Scholar Wesam M. El-Raghi Wesam M. El-Raghi 2Botany Department, Faculty of Science, Damietta University, Damietta, Egypt Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2016) 65 (5): 431–440. https://doi.org/10.2166/aqua.2016.115 Article history Received: November 28 2015 Accepted: March 12 2016 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Cite Icon Cite Permissions Search Site Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsThis Journal Search Advanced Search Citation Zakaria A. Mohamed, Mohamed Ali Deyab, Mohamed I. Abou-Dobara, Wesam M. El-Raghi; Occurrence of toxic cyanobacteria and microcystin toxin in domestic water storage reservoirs, Egypt. Journal of Water Supply: Research and Technology-Aqua 1 August 2016; 65 (5): 431–440. doi: https://doi.org/10.2166/aqua.2016.115 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Residents in many developing countries store treated drinking water in tanks or reservoirs because of intermittent and infrequent water supplies. Many studies have focused on bacterial contamination of domestic reservoir waters, the cyanobacterial and algal contamination is largely unexplored. Therefore, the present study investigates toxic cyanobacteria and their microcystin (MC) toxins in some domestic water storage reservoirs in Egypt as an example for developing countries. Three phytoplankton groups including cyanobacteria, green algae and diatoms were found in domestic reservoirs. Among these species, the toxic cyanobacterium Microcystis aeruginosa had the highest cell density during warm months (4.2–5.92 cells × 106 L–1). This cell density increased along the time, indicating that environmental conditions in these reservoirs promoted the proliferation of this species. Intra- and extracellular MCs were also detected in reservoir waters at concentrations of 3.5–40 and 1–7.6 μg L–1, respectively, exceeding the WHO guideline limit of 1 μg L–1 for these toxins in drinking water. Heterotrophic bacteria were found in association with cyanobacteria in reservoir waters. The study suggests that treated-water storage reservoirs should be monitored for the presence of toxic cyanobacteria to protect the public from exposure to their potent toxins. cyanobacteria, domestic reservoirs, drinking water, hygienic risk, microcystins © IWA Publishing 2016 You do not currently have access to this content.