Cloning and expression of the catalase gene (KatA) from Pseudomonas aeruginosa and the degradation of AFB by recombinant catalase.

Background: Aflatoxin B (AFB ) poses a severe threat to human and animal health. Countries worldwide have invested considerable manpower and material resources in degrading aflatoxins. Enzyme degradation is the most efficient and environmentally friendly approach for modifying aflatoxin into less toxic molecules. Catalase is commonly used as a detoxification agent to decrease the contamination levels of aflatoxins in animal feeds. This study aimed to obtain recombinant catalase via gene engineering and determined whether a recombinant catalase could degrade AFB .

Results: The catalase gene (KatA) from Pseudomonas aeruginosa was cloned and expressed in Escherichia coli, and the expression conditions of this recombinant catalase were optimized. The recombinant catalase was isolated and purified using Ni-chelating affinity chromatography, and its ability to degrade AFB was evaluated. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the expressed of catalase was approximately 55.6 kDa, which was subsequently purified using Ni-chelating affinity chromatography. The degradation rate of AFB by recombinant catalase in the presence of syringaldehyde was 38.79%.

Conclusion: The degradation of AFB by a recombinant catalase has been reported for the first time. This study provides a new paradigm for the use of recombinant catalases in degrading AFB in food and feed. © 2022 Society of Chemical Industry.