Impacts of Different Phosphorus Contents on the Growth of Cylindrospermopsis raciborskii in the Aquatic Environment

Cyanobacteria are the most important group of algae. Many factors are involved in the rapid growth of algae such as phosphorus and nitrogen contents. The current study aimed at evaluating the effect different phosphorus concentrations on the growth rate of Cylindrospermopsis raciborskii during the aquatic life. The experiment was carried out for 12 days at three phosphorus concentrations and one control group in Zehnder 8 and Blue-Green 11 media. The rates of cell division per day (G) and specific growth rate () were separately estimated for each group. Cyanobacterium was tested at three phosphorus concentrations; 150, 300, and 600 g/L. The current study results showed that increasing phosphorus concentration had a significant effect on the growth of C. raciborskii in some particular days of cultivation. The maximum growth rate (0.9 per day) was observed at 7 g/L phosphorus concentration. Phosphorus was a limiting factor and contributed to the removal of toxins from the alga and its blooming. The maximum growth rate was observed in the group treated on the day 8 of cultivation with phosphorus concentration of 300 g/L.