Enhancing Protease and Amylase Activities in <i>Bacillus licheniformis</i> XS-4 for Traditional Soy Sauce Fermentation Using ARTP Mutagenesis
Andong Zhang,
Yudong Ma,
Yue Deng,
Zhiwei Zhou,
Yue Cao,
Bin Yang,
Jing Bai,
Qun Sun
Affiliations
Andong Zhang
Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
Yudong Ma
Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
Yue Deng
School of China Alcoholic Drinks, Luzhou Vocational and Technical College, Luzhou 646000, China
Zhiwei Zhou
Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
Yue Cao
Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
Bin Yang
Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
Jing Bai
Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
Qun Sun
Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
This study was conducted to increase the enzymatic activity of Bacillus licheniformis XS-4, which was isolated from the traditional fermented mash of Xianshi soy sauce. The mutation was induced by atmospheric and room-temperature plasma (ARTP), and a mutant strain, mut80, was obtained. mut80 exhibited significant increases in protease and amylase activity by 90.54% and 143.10%, respectively, and the enhanced enzymatic activities were stably maintained after 20 consecutive incubations. Re-sequencing analysis of mut80 revealed that the mutation sites were located in 1518447(AT-T) and 4253106(G-A) in its genome, which was involved in the metabolic pathways of amino acids. The expression of the protease synthetic gene (aprX) increased 1.54 times, while that of the amylase gene (amyA) increased 11.26 times, as confirmed via RT-qPCR. Using ARTP mutagenesis, the present study proposes a highly efficient microbial resource with enhanced protease and amylase activity provided by B. licheniformis, which can potentially be used to improve the efficiency of traditional soy sauce fermentation.
