Enzyme activity of malate dehydrogenase after μAPPJ treatment. Residual enzyme activity was determined either directly after 1 min plasma treatment (t0, dark bars) or after incubation at 37°C for 20 min (t20, light bars) in the following strains: E. coli wild type harboring the empty vector pCA24N (wt+ev), E. coli pCA24N::sodA (5 μM IPTG) (oe sodA), E. coli pCA24N::katE (5 μM IPTG) (oe katE), and E. coli pCA24N::sodA::katE (5 μM IPTG) (oe sodA+katE). Averages and standard deviations represent three independent biological replicates.