Improved Recombinant Expression of Maltogenic α-Amylase AmyM in Bacillus subtilis by Optimizing Its Secretion and NADPH Production

The maltose α-amylase AmyM from Bacillus stearothermophilus can be used for flour modification, baked goods preservation, and production. Here, we optimized the recombinant expression of in subtilis WB800 via several strategies. By screening optimal promoter, a double promoter combination (P43 PamyL) could improve level by 61.25%, compared with strong P43. Then, secretion efficiency over-expressing molecular chaperone prsA gene. SDS-PAGE results suggested that over-expression to extracellular environment. enzyme activity was increased 101.58% control strain. To further AmyM, introduced hemoglobin gene Vitreoscilla (vgb) into revealed introduction vgb promote transcription translation B. subtilis. This may due increasing intracellular NADPH NADP+ caused vgb. this strategy, 204.08%. Finally, found showed an temperature 65 °C pH 5.5. Our present provided effective strategy heterologous