Maximum amylase titer of B. pumilus Jo2.1 cultivations deploying various promoters in the pHP49 backbone. Jo2.1/pHP5-31 (Pref) was initially cultivated under optimized protease process conditions (bar with grey background). Strains containing the plasmid encoded promoter Pref, P
apr E1 III and P
apr E2 were cultivated under aligned process conditions in respect to modified pH setpoint (bars with white background). Based on a harshly decreased process robustness expressing the amylase in the protease process, bars represent the maximum achieved amylase titer of four independent cultivations per strain. Yielded amylase concentrations are scaled to B. licheniformis protease BL18 titer at the same scale serving as industrial relevant reference.