Recent progress in ergothioneine biosynthesis: a review / 生物工程学报

Ergothioneine is a multifunctional physiological cytoprotector, with broad application in foods, beverage, medicine, cosmetics and so on. Biosynthesis is an increasingly favored method in the production of ergothioneine. This paper summarizes the new progress in the identification of key pathways, the mining of key enzymes, and the development of natural edible mushroom species and high-yield engineering strains for ergothioneine biosynthesis in recent years. Through this review, we aim to reveal the molecular mechanism of ergothioneine biosynthesis and then employ the methods of fermentation engineering, metabolic engineering, and synthetic biology to greatly increase the yield of ergothioneine.

Construction and optimization of ergothioneine-producing Escherichia coli / 生物工程学报

Ergothioneine (ERG) is a natural antioxidant that has been widely used in the fields of food, medicine and cosmetics. Compared with traditional plant extraction and chemical synthesis approaches, microbial synthesis of ergothioneine has many advantages, such as the short production cycle and low cost, and thus has attracted intensive attention. In order to engineer an ergothioneine high-yielding Escherichia coli strain, the ergothioneine synthesis gene cluster egtABCDE from Mycobacterium smegmatis and egt1 from Schizosaccharomyces pombe were introduced into E. coli BL21(DE3) to generate a strain E1-A1 harboring the ergothioneine biosynthesis pathway. As a result, (95.58±3.2) mg/L ergothioneine was produced in flask cultures. To further increase ergothioneine yield, the relevant enzymes for biosynthesis of histidine, methionine, and cysteine, the three precursor amino acids of ergothioneine, were overexpressed. Individual overexpression of serAT410STOP and thrA resulted in an ergothioneine titer of (134.83±4.22) mg/L and (130.26±3.34) mg/L, respectively, while co-overexpression of serAT410STOP and thrA increased the production of ergothioneine to (144.97±5.40) mg/L. Eventually, by adopting a fed-batch fermentation strategy in 3 L fermenter, the optimized strain E1-A1-thrA-serA* produced 548.75 mg/L and 710.53 mg/L ergothioneine in glucose inorganic salt medium and rich medium, respectively.