Production of recombinant beta-amylase of Bacillus aryabhattai

Abstract

In this study, the effects of carbon source, nitrogen source, and metal ions on cell growth and Bacillus aryabhattai β-amylase production in recombinant Brevibacillus choshinensis were investigated. The optimal medium for β-amylase production, containing glucose (7.5 g·L⁻¹), pig bone peptone (40.0 g·L⁻¹), Mg²⁺ (0.05 mol·L⁻¹), and trace metal elements, was determined through single-factor experiments in shake flasks. When cultured in the optimized medium, the β-amylase yield reached 925.4 U mL⁻¹, which was 7.2-fold higher than that obtained in the initial medium. Besides, a modified feeding strategy was proposed and applied in a 3-L fermentor fed with glucose, which achieved a dry cell weight of 15.4 g L⁻¹. Through this cultivation approached 30 °C with 0 g·L⁻¹ initial glucose concentration, the maximum β-amylase activity reached 5371.8 U mL⁻¹, which was 41.7-fold higher than that obtained with the initial medium in shake flask.

Keywords:

• Bacillus aryabhattai
• Brevibacillus choshinensis
• optimization of production
• recombinant β-amylase

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (31401636), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and Program for the Top Young Talents of Nanjing Forestry University (Number GXL2018010).