Degradation of Penicillin G by Visible Light Irradiation-Assisted Biotransformation by Whole Cell paracoccus sp .

Abstract

Background: The Paracoccus sp. strain (KDSPL-02) isolated from sludge was identified and evaluated for catalytic activity in the degradation of penicillin G. Results: High degradation efficiency and synergistic catalytic effects of the whole cell and visible light without additional catalysts were observed. The key factors influencing the degradation and kinetics of penicillin G were investigated. The results showed the phenylacetic acid, which was produced during penicillin G biodegradation, exhibited stronger inhibiting effects on KDSPL-02. However, this effect was reduced by visible light irradiation without any additional photocatalyst; furthermore, the rate of penicillin G biodegradation was accelerated, reaching a 100% rate in 12 h at a penicillin G concentration of 1.2 g/L. Four key intermediates produced during penicillin G degradation were isolated and identified by LC–MS, 1H NMR, and 13C NMR. Enzymes involved in the PAA pathway were proposed from a genomic analysis of paracoccus sp. KDSPL-02. Conclusions:These results provide a new method for bio-degrading of penicillin or other antibiotic pollutants using photoaccelerating biocatalysts with greater efficiency and more environmentally friendly conditions.