Fig. 6

Optimization of plasmid PET22b-E. coli induced conditions (Calculated with a conversion rate of 100% under optimal single factor conditions. (a) The effect of culture medium on enzyme activity. (b) The effect of induction temperature on enzyme activity. (c) The effect of induction Metal ion on enzyme activity. (d) The effect of induction OD600 enzyme activity. (e) The effect of inducer concentration on enzyme activity. (f) The effect of induction time on enzyme activity. ns, no significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Data are expressed as the mean ± standard deviation (SD) of 3 independent experiments.