Heterologous and High Production of Ergothioneine in Bacillus licheniformis by Using Genes from Anaerobic Bacteria

Purpose: This study aimed to utilize genetically engineeredBacillus licheniformisfor the production of ergothioneine (EGT). Given the value of EGT and the application ofBacillus licheniformisin enzyme preparation production, we cloned the key enzymes (EanA and EanB) fromChlorbium limicola. Through gene alignment, new ergothioneine synthase genes (EanAN and EanBN) were identified and then expressed inBacillus licheniformisto construct strains. Additionally, we investigated the factors influencing the yield of EGT and made a comparison withEscherichia coli. Methods: The relevant genes were cloned and transferred intoBacillus licheniformis. Fermentation experiments were conducted under different conditions for yield analysis, and the stability of this bacterium was also evaluated simultaneously. Results: The constructed strains were capable of producing EGT. Specifically, the yield of the EanANBN strain reached (643.8 ± 135) mg/L, and its stability was suitable for continuous production. Conclusions: Genetically engineeredBacillus licheniformisdemonstrates potential in the industrial-scale production of EGT. Compared withEscherichia coli, it has advantages, thus opening up new possibilities for the application and market supply of EGT.