# Recombinant Expression and Bioprocess Optimization of Priestia megaterium α‐Amylase and Its Impact on Dough Fermentation Efficiency

## TL;DR

This paper optimizes the production of an α-amylase enzyme from Priestia megaterium and shows it works nearly as well as commercial enzymes in dough fermentation.

## Contribution

First optimization of Priestia megaterium α-amylase production using biomass/IPTG ratio in a controlled bioprocess.

## Key findings

- Fed-batch fermentation achieved 67.7 U mL−1 α-amylase activity at 22.3 g L−1 biomass.
- PmAmy showed 99% dough fermentation efficiency compared to commercial α-amylase.
- Optimized conditions included 1.0 vvm airflow, 37°C, and pH 7.0 with a biomass-to-IPTG ratio of 20 gbiomass mmolIPTG−1.

## Abstract

α‐Amylase is a key hydrolytic enzyme in starch degradation, playing a crucial role in industrial bioprocesses such as dough fermentation. However, optimizing α‐amylase production remains challenging due to variations in microbial sources, culture conditions, and induction strategies. In this study, Priestia megaterium α‐amylase (PmAmy) production was optimized for the first time based on the biomass/IPTG ratio in a controlled bioprocess. The impact of enzyme supplementation with equal quantity and enzymatic activity on dough fermentation was also evaluated to ensure consistent performance and effective application. Under the bioprocess conditions of 1.0 vvm airflow, 37°C, and 1000 rpm, a biomass‐to‐IPTG ratio was optimized as 20 gbiomass mmolIPTG
−1 at pH 7.0. Fed‐batch fermentation was conducted at a specific growth rate of µ = 0.22 h−1 for 22 h, yielding an α‐amylase activity of 67.7 ± 4.0 U mL−1 at a cell concentration of 22.3 ± 5.3 g L−1 Dough fermentation trials demonstrated 99% efficiency compared to commercial α‐amylase, despite PmAmy being in its primary recovery form. These findings highlight its potential for industrial baking applications. This study offers a scalable and sustainable enzyme production strategy, contributing to improved fermentation efficiency, product quality, and economic feasibility in food biotechnology.

This study presents a scalable strategy for producing Priestia megaterium α‐amylase (PmAmy) via fed‐batch fermentation, optimizing the biomass/IPTG ratio to enhance yield. With an activity of 67.7 U mL−1 at 22.3 g L−1 biomass, PmAmy demonstrated 99% efficiency in dough fermentation, highlighting its industrial potential as a sustainable baking enzyme
.