The effect of oxytetracycline and florfenicol antibiotics on growth, chlorophyll a and total protein to microalgae Chaetoceros muelleri (Lemmermann, 1898)

The study aimed to examine the chronic toxicity effects of oxytetracycline (OTC) and florfenicol (FLO) antibiotics, commonly used in shrimp farms, on the growth performance, chlorophyll a content, and total protein of Chaetoceros muelleri microalgae. C. muelleri, initially at a density of 4,000 cells per milliliter, underwent exposure to oxytetracycline at doses of 7.43 milligrams per liter and florfenicol at 5.20 milligrams per liter for 12 days. Subsequent assessments focused on growth metrics, chlorophyll a content, and total protein. The findings highlighted a significant reduction in the growth, chlorophyll a content, and protein synthesis of C. muelleri following exposure to both OTC and FLO antibiotics (p < 0.05). Moreover, the study revealed that FLO exhibited higher toxicity toward C. muelleri compared to OTC. The observed decline in growth, chlorophyll a content, and protein synthesis in C. muelleri under OTC and FLO exposure could be attributed to the inhibitory impact of these antibiotics on cellular respiration and protein synthesis pathways.