Investigation of pharmaceutical compounds ( Metronidazole, Rosuvastatin and Codeine phosphate) removal by Synechocystis sp. PCC6803 microalgae and effects of the drugs on growth, pigments, protein and lipid contents
The uncontrolled entry of pharmaceutical compounds (PCs) into water sources causes irreversible damages to microorganisms. The aim of this study was to evaluate the ability of Synechocystis sp. PCC6803 microalgae to remove three dangerous contaminants including Metronidazole, Rosuvastatin, and Codeine phosphate at three concentrations, 1, 3 and 5 mg/L, 200, 400 and 600 mg/L, and 50, 150 and 250 mg/L, respectively. Adding Metronidazole to the culture medium resulted in 70% reduction in biomass produced; while the amount of protein produced at concentration of 5 mg/L increased about 3 times compared to the control culture. The culture medium containing 600 mg/L Rosuvastatin increased the total lipid production by more than 50%. The biomass and protein produced in culture medium containing Codeine phosphate was not significantly different compared with the control. Moreover, the drugs removal efficiency of Synechocystis was 80% for Metronidazole and an almost total removal for Rosuvastatin and Codeine Phosphate. Metronidazole which is a lipophilic drug binded to the cell surface microalgae through the formation of chemical bonds between its aromatic rings and functional groups on the surface of extracellular substrates. However, Rosuvastatin and Codeine phosphate which are hydrophilic drugs can enter the cells, where they are degraded by intra-cellular enzymatic mechanism; thus, they were removed by cell biodegradation mechanism in cells.