Center for Energy Conservation and Emission Reduction in Fermentation Industry in Inner Mongolia, Inner Mongolia University of Technology, Hohhot, China.
Engineering Research Center of Inner Mongolia for Green Manufacturing in Bio-Fermentation Industry, Inner Mongolia University of Technology, Hohhot, China.
Appl Biochem Biotechnol. 2023 Jan;195(1):68-85. doi: 10.1007/s12010-022-04097-y. Epub 2022 Aug 15.
To improve fermentative production of α-amylase, heavy-ion mutagenesis technology was used to irradiate Bacillus subtilis (B. subtilis) to obtain the high yielding mutants in this study. After continuous cultivation for 12 generations, eight mutants exhibited positive mutation rate with greater H/C. The α-amylase production was stable and obviously exceeded that by the parent strain, which shows that the mutants have a good genetic stability. Among the mutants, the α-amylase activity of B. subtilis KC-180-2 was 72.26 U·mL, which was 82.34% higher than that of the original strain. After optimization of fermentation conditions and media, the α-amylase activity of B. subtilis KC-180-2 reached a maximum of 156.83 U·mL at 36 h in a bioreactor. In addition, the optimized fermentation temperature of B. subtilis KC-180-2 was increased to 49℃, indicating B. subtilis KC-180-2 possesses high-temperature resistance, which has great application prospects for industrial fermentation for α-amylase production.
为了提高α-淀粉酶的发酵生产水平，本研究采用重离子诱变技术对枯草芽孢杆菌（Bacillus subtilis）进行辐照，以获得高产突变株。经过 12 代连续培养，有 8 株突变株的 H/C 值较高，表现出正突变率。其α-淀粉酶产量稳定，明显高于出发菌株，说明突变株具有良好的遗传稳定性。在这些突变株中，枯草芽孢杆菌 KC-180-2 的α-淀粉酶活力达到 72.26 U·mL-1，比原始菌株提高了 82.34%。经过发酵条件和培养基的优化，枯草芽孢杆菌 KC-180-2 在生物反应器中于 36 h 时达到最大酶活 156.83 U·mL-1。此外，优化后的枯草芽孢杆菌 KC-180-2 的发酵温度提高到 49℃，表明枯草芽孢杆菌 KC-180-2 具有耐高温的特性，在α-淀粉酶的工业发酵生产中具有广阔的应用前景。
