Figure 4

Effect of deletion of matAB on tyrosinase production by S. lividans . Transformants of the parental strain S. lividans 66 (grey curves) and its matAB null mutant (black curves) contained plasmid pIJ703, leading to the expression of tyrosinase (lines with blocks) from S. antibioticus. Strains were grown in 1.3 L bench-top bioreactors with a 900 ml working volume on TSBS medium with 25 μM CuCl₂. CO₂ production (continues lines) was calculated by measuring the concentration in the off gas and tyrosinase activity was measured spectrophotometrically. The CO₂ production and tyrosinase activity is the average of three separate experiments. Error bars in the biomass graphs represent the standard error of the mean and the CO₂ had a deviation of less than 5%.