Abstract

SOTELO-CORNEJO, Karen Griselda et al. Effect of photolysis and pH on the degradation of oxytetracycline in sediment and seawater. TIP [online]. 2021, vol.24, e369.  Epub Apr 17, 2023. ISSN 1405-888X.  https://doi.org/10.22201/fesz.23958723e.2021.369.

Oxytetracycline (OTC) is an antibiotic frequently used in the control of diseases caused by Vibrio in Penaeus vannamei shrimp farms. The degradation of OTC was evaluated in samples of sediment and seawater (2:98 w/v), one with an OTC standard and another with OTC in shrimp feed, both at 10 μgmL-1. The tests lasted 40 days, and the abiotic factors were evaluated, such as the exposure to light, and the effect of the pH (7 and 8). The samples with OTC standard exposed to light, had a degradation of the antibiotic of 100% for both pH values; In the unexposed samples to light, the degradation was 88.33% at pH 7 and 90.90% at pH 8. In the samples with OTC in shrimp feed, the degradation was 100% at 40 days, with and without exposure to light, at different pH values. The half-life time of OTC degradation in shrimp feed was lower with due to the samples added with standard with and without exposure to light (P ≤ 0.05). OTC residues can be degraded by the effect of light and pH, reducing their permanence in aquaculture sediments.

Keywords : oxytetracycline; sediment and seawater; shrimp feed; bacterial resistance.