Porphyrin mediated photodegradation of tylosin in aqueous media by near-UV light

Authors: Avramenko, Aleksandr; Spiehs, Mindy

Submitted to: Photochemistry and Photobiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2023
Publication Date: 7/1/2023
Citation: Avramenko, A.G., Spiehs, M.J. 2023. Porphyrin mediated photodegradation of tylosin in aqueous media by near-UV light. Photochemistry and Photobiology, A: Chemistry. 441. Article 114698. https://doi.org/10.1016/j.jphotochem.2023.114698.
DOI: https://doi.org/10.1016/j.jphotochem.2023.114698

Interpretive Summary: Tylosin is an antibiotic that is often used in agriculture. However, after it is given to an animal a portion of the administered dose is excreted into the environment. Processes such as rain can spread this to nearby water sources. Tylosin exposure to other animals by drinking from affected water sources may cause the development of antibiotic resistance. For this reason, there is a need to design a technique to effectively remove this molecule from water sources. One approach to overcome this problem is through the use of a molecule such as porphyrin, which is a building block of chlorophyll and strongly absorbs blue light. It was found that the addition of porphyrin derivatives to deionized water containing 0.1 mM tylosin caused the tylosin concentration to decrease. Specifically, tylosin water mixed with octoethylporphyrin and subsequently exposed to blue light for 3 hours, produced a 13.88% decrease. In addition, a decline in the tylosin concentration by 21.20% was yielded with the water source being exposed to copper (II) tetraphenylporphyrin. This study suggests we may be able to use blue light to decrease tylosin concentration in water sources.

Technical Abstract: Tylosin is one of the most used livestock antibiotics, typically employed as a prophylactic and a growth promoter. However, there have been growing concerns that the presence of antibiotics in wastewater sources can contribute to the development of antibiotic resistance. Thus, attempts have been made by researchers to develop techniques capable of removing antibiotics from wastewater. This study evaluated the photocatalytic properties of three types of porphyrin molecules to break down tylosin in deionized water. It was observed that when irradiated with 3.06 eV light the concentration of tylosin decreases by 13.88% after 180 min in the presence of octoethylporphyrin. Similarly, after 180-minute exposure the concentration of tylosin decreases by 17.92% in the presence of tetraphenylporphyrin. Lastly, in the presence of copper (II) tetraphenylporphyrin the concentration of tylosin was observed to decrease by 21.20% after 180-minute exposure to near UV light. Furthermore, it was observed that in the presence of CuTPP the concentration of tylosin decreased by up to 12.54% in a pond water sample over a 24 h period. The initial results indicate that porphyrins present as a plausible candidate for organic photocatalysts to facilitate removal of antibiotic contaminants from aquatic sources.