De Novo Biosynthesis of Antidepressant Psilocybin in Escherichia coli
Microbial Biotechnology April 1, 2025 Zhangrao Huang, Yongpeng Yao, Rong Di et al. 12 citations
Psilocybin, a tryptamine-derived alkaloid with Breakthrough Therapy designation for treatment-resistant depression, was synthesized de novo in Escherichia coli by engineering the fungal cytochrome P450 enzyme PsiH. Modifications to PsiH's N-terminal domain and expression of the entire biosynthetic pathway at low temperature improved enzyme activity. Enhancing precursor supply and the P450 electron transfer chain increased norbaeocystin titers 33-fold (to 105.3 mg/L) and psilocybin titers 17-fold (to 14 mg/L). Overexpressing an extra copy of the methyltransferase gene psiM further boosted psilocybin production. Optimizing flask fermentation conditions yielded 79.4 mg/L of psilocybin, a 100-fold improvement over the starting strain, advancing sustainable microbial production of this antidepressant.