Construction of engineering bacteria for manganese oxidation and degradation of aureomycin by biogenic manganese oxides

Aureomycin (CTC) is a commonly used tetracycline antibiotic that causes water and soil pollution and greatly endangers the environment and human health. Microbial degradation to remove residual antibiotics in wastewater is of growing interest. Due to its unique structure and excellent oxidative properties, biogenic manganese oxides (BMO) has been widely studied in the field of water pollutant removal. However, the current preparation of BMO generally suffers from low yield and insufficient production efficiency. In this paper, an efficient manganese-oxidizing bacterium Bacillus sp. D-1 was isolated. Manganese-oxidizing engineering bacteria were constructed to achieve rapid and sufficient BMO production, and the structure and function of the BMO was characterized. SEM was used to characterize the layered structure of the nanoparticles. XPS and XRD were used to determine that the mixture was composed of manganese species with three valence states. BMO was used to degrade 10 mg·L −1 CTC, and the CTC removal rate reached 93.2 % in 24 h, with an optimal reaction pH of 7.6. Finally, LCMS and ECOSAR were used to analyze the oxidative degradation products of CTC and their biological toxicity. Therefore, this paper successfully constructed a high-performance manganese-oxidizing engineering bacterium, revealed the efficient degradation mechanism of CTC by BMO, provided a new strategy for the green treatment of combined pollution of manganese and antibiotics in water bodies, and realized the continuous removal of manganese and water pollutants.