Ergothioneine production by Corynebacterium glutamicum harboring heterologous biosynthesis pathways

Available online 2 November 2022 In this study, Corynebacterium glutamicum was engineered to produce ergothioneine, an amino acid derivative with high antioxidant activity. The ergothioneine biosynthesis genes, egtABCDE, from Mycolicibacterium smegmatis were introduced into wild-type and L-cysteine-producing strains of C. glutamicum to evaluate their ergothioneine production. In the L-cysteine-producing strain, ergothioneine production reached approximately 40 mg LL1 after 2 weeks, and the amount was higher than that in the wild-type strain. As C. glutamicum possesses an ortholog of M. smegmatis egtA, which encodes an enzyme responsible for g-glutamyl-L-cysteine synthesis, the effect of introducing egtBCDE genes on ergothioneine production in the L-cysteine-producing strain was evaluated, revealing that a further increase to more than 70 mg LL1 was achieved. As EgtBs from Methylobacterium bacteria are reported to use L-cysteine as a sulfur donor in ergothioneine biosynthesis, egtB from Methylobacterium was expressed with M. smegmatis egtDE in the L-cysteine-producing strain. As a result, ergothioneine production was further improved to approximately 100 mg LL1. These re-sults indicate that utilization of the L-cysteine-producing strain and introduction of heterologous biosynthesis pathways from M. smegmatis and Methylobacterium bacteria are effective for improved ergothioneine production by C. glutamicum.(c) 2022, The Society for Biotechnology, Japan. All rights reserved.