Effect of Tetracycline and Ciprofloxacin on Growth and Biochemical Composition of Chlorella Vulgaris

This research aimed to evaluate the impacts of Tetracycline (TC) and Ciprofloxacin (CIP) on the growth and biochemical composition of Chlorella vulgaris. In this regard, TC and CIP were added to C. vulgaris culture media at concentrations of 5, 10, 30, and 50 mg L-1. The effects on growth, antibiotic removal efficiency, and biochemical composition of microalgal cells in terms of chlorophyll, carotenoid, protein, and lipid contents were investigated over a 14-day period. Using both TC and CIP, the highest removal efficiencies (92.0 and 82.2 %, respectively) were observed at an antibiotic concentration of 5 mg L-1, while the highest final biomass concentrations (0.43 and 0.54 g L-1) were obtained at TC and CIP concentrations of 10 and 30 mg L-1, respectively. It is noteworthy that, despite the growth limitation at high concentrations of the antibiotics, the microalga exhibited resilience and survival. As the TC and CIP concentration was raised in the medium, a decrease in chlorophyll, carotenoid, and protein contents occurred compared to the control medium. Conversely, at a TC and CIP concentration of 50 mg L-1, the lipid content increased up to 28.68 and 27.51 %, respectively. This study provides valuable insights into the response of C. vulgaris to specific antibiotic-induced stress, shedding light on both growth patterns and biochemical composition of this microalga under such conditions.