Codon Optimization Significantly Improves the Expression Level of α-Amylase Gene from Bacillus licheniformis in Pichia pastoris

Figure 5

Influence of pH on activity and stability of recombinant BlAmy (a) and deglycosylated recombinant BlAmy (b). -Amylase activity was determined by starch-iodine color method. Optimal pH was determined by assessing the activity of the purified recombinant BlAmy at pH 4.0–11.0. The relative activity at different pH values was calculated by setting pH 7.0 as 100%. The pH stability was determined by measuring the residual enzyme activities after incubating purified recombinant BlAmy at various pH for 24 h at 30°C. The residual activity was calculated by taking the activity of purified recombinant BlAmy without buffer treatment as 100%. All measurements were carried out in triplicate.

(a)

(b)