Increasing chitosanase production in Bacillus cereus by a novel mutagenesis and screen method

ABSTRACT

Chitosan hydrolysis by chitosanase is one of the most effective methods to produce chitosan oligosaccharides. One of the prerequisites of enzyme fermentation production is to select and breed enzyme-producing cells with good performance. So in the process of fermentation production, the low yield of chitosanase cannot meet the current requirement. In this paper, a strain producing chitosanase was screened and identified, and a novel mutagenesis system (Atmospheric and Room Temperature Plasma (ARTP)) was selected to increase the yield of chitosanase. Then, the fermentation medium was optimized to further improve the enzyme activity of the strain. A strain of Bacillus cereus capable of producing chitosanase was screened and identified from soil samples. A mutant strain of B.cereus was obtained by Atmospheric and Room Temperature Plasma mutagenesis and bioscreening method, and chitosanase activity was 2.49 folds that of the original bacterium. After an optimized fermentation medium, the enzyme activity of the mutant strain was 1.47 folds that of the original bacterium. Combined with all the above optimization experiments, the enzyme activity of mutant strain increased by 3.66 times. The results showed that the Atmospheric and Room Temperature Plasma mutagenesis and bioscreening method could significantly increase the yield of chitosanase in B.cereus, and had little effect on the properties of the enzyme. These findings have potential applications in the mutagenesis of other enzyme-producing microorganisms.

KEYWORDS:

• Bacillus cereus
• chitosanase
• screening
• identification
• atmospheric and Room Temperature Plasma Mutagenesis

Research highlights

1. We screened and identified a chitosanase-producing strain from the soil.

2. The activity of chitosanase was improved by ARTP mutagenesis and had little effect on the properties of the enzyme.

3. The enzyme activity of chitosanase was greatly improved by optimizing the fermentation medium of the mutant strain.

4. It has potential application value in mutagenesis of other enzyme-producing microorganisms.

Acknowledgements

The authors would like to thank the Key Laboratory of the Ministry of Education Industrial Fermentation Microbiology.

Authors contributions

All authors read and approved the final manuscript.

Disclosure statement

The authors declare that they have no competing interests.

Ethics approval and consent to participate

This paper is in compliance with ethical standards.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Foundation (No.2020KF005, 2020KF009) of Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education and Tianjin Key Lab of Industrial Microbiology (Tianjin University of Science &Technology).