ZEN degradation activity assay of Prx found more than 95.2% of ZEN was degraded in the crude extract of BL21(DE3) Prx by IPTG induction after 4 h incubation, whereas no significant reduction of ZEN was found in crude extract of BL21(DE3) Prx no induced after 4 h incubation. Further, recombinant Prx in crude extract was purified by phenyl Sepharose column and Sephadex G-75 column, Fig. 3 showed the SDS-PAGE results of purified recombinant Prx protein concentrations is 4.28 mg ml−1 in crude recombinant Prx solution, and 1.12 mg ml−1 in purified recombinant Prx solution.
ZEN degradation activity of purified recombinant Prx was measured in the various temperatures and various pH conditions. Results found the optimum pH for the purified recombinant Prx was 9.0 at 30 °C (Fig. 5), and the optimum temperatures for the purified Prx activities were 70 °C (Fig. 6).