Figure 4
β-lactamase activity of P. stutzeri A15 pEstA β - bla , pEstA- bla and pEstA*- bla. Relative β-lactamase activity of whole cells of P. stutzeri A15 pEstAβ-estAP, pEstAβ-bla, pEstA-bla, pEstA*-bla or empty vector (EV) assessed with nitrocefin as the substrate. Data represent the mean of three independent repeats ± 95% confidence interval. The significance level (P < 0.05) as determined by one-way ANOVA with Student-Newman-Keuls as post-hoc analysis is indicated with a letter code.