Reducing residual chlortetracycline in wastewater using a whole-cell biocatalyst.
Minrui Liu, Chuangxin Wang, Xing-E Qi, Shaobo Du, Hongyuhang Ni
Author Information
Minrui Liu: College of Life Science and Technology, Gansu Agricultural University, Lanzhou Gansu730070, China. Electronic address: liumr@gsau.edu.cn.
Chuangxin Wang: College of Life Sciences, Northwest Normal University, Lanzhou, Gansu 730070, China.
Xing-E Qi: College of Life Science and Technology, Gansu Agricultural University, Lanzhou Gansu730070, China.
Shaobo Du: College of Life Science and Technology, Gansu Agricultural University, Lanzhou Gansu730070, China.
Hongyuhang Ni: Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong.
Antibiotic contamination has become an increasingly important environmental problem as a potentially hazardous emergent and recalcitrant pollutant that poses threats to human health. In this study, manganese peroxidase displayed on the outer membrane of Escherichia coli as a whole-cell biocatalyst (E. coli MnP) was expected to degrade antibiotics. The manganese peroxidase activity of the whole-cell biocatalyst was 13.88 ± 0.25 U/L. The typical tetracycline antibiotic chlortetracycline was used to analyze the degradation process. Chlortetracycline at 50 mg/L was effectively transformed via the whole-cell biocatalyst within 18 h. After six repeated batch reactions, the whole-cell biocatalyst retained 87.2 % of the initial activity and retained over 87.46 % of the initial enzyme activity after storage at 25°C for 40 days. Chlortetracycline could be effectively removed from pharmaceutical and livestock wastewater by the whole-cell biocatalyst. Thus, efficient whole-cell biocatalysts are effective alternatives for degrading recalcitrant antibiotics and have potential applications in treating environmental antibiotic contamination.
