Tetracycline Biodegradation by Shigella flexneri strain TA_E_3 Isolated from Wastewater Treatment Plant

Although the transformation of tetracycline (TEC) by abiotic mechanisms has been extensively reported in literature, knowledge on the potential degradation of TEC by microbial activities in aquatic environments is still scarce. Some limitations are present for tetracycline biodegradation including the typical metabolite products that have been produced by the Shigella flexneri TA_E_3. Therefore, the purpose of this study is to investigate the by-products produced during biodegradation of tetracyclines by using Shigella flexneri TA_E_3 as model, and to determine the possible TEC degradation by-products and metabolic pathway. The changes in the concentration of the TEC were measured within 6 hours of degradation. TEC degradation by-products produced from biodegradation by strain TA_E_3 have been studied. The result shows that danazol is the main biodegradation product identified using LC-MS Q TOF analysis. Potential degradation pathways were then proposed including the removal of amide, carbonyl, and amine groups, alongside the isomerisation of the parent compound. The findings of this work can serve as a theoretical foundation for more accurate predictions of antibiotic destiny, transit, and degradation in aquatic environments.