Psychedelic tryptamines such as DMT, 5-MeO-DMT, and bufotenine, found naturally in plants and animals, show clinical promise for treating anxiety and depression. Using genetic and metabolic engineering, researchers developed a biosynthetic pathway in Escherichia coli to produce these compounds. With tryptophan supplementation, DMT reached maximum titers of 74.7 ± 10.5 mg/L in fed-batch 2-L bioreactors. De novo DMT production from glucose achieved 14.0 mg/L, and the study reports the first microbial production of 5-MeO-DMT and bufotenine in vivo. This work establishes a foundation for further optimization toward industrial-scale production.
Psilocybin, the prodrug to the psychoactive compound in 'magic' mushrooms, is being studied as a treatment for depression and anxiety. Previous biosynthesis in E. coli using genes from Psilocybe cubensis achieved maximum titers of 1.16 g/L. This work tested genes from four psilocybin-producing mushroom species and found that psiD and psiK from P. cubensis performed best, while psiM from Psilocybe cyanescens increased selectivity for the intermediate baeocystin. The strain Gymdi30, with psiM from Gymnopilus dilepis, produced 1.46 ± 0.13 g/L psilocybin, the highest reported titer to date. Comparative proteomic analysis during high and low productivity identified metabolic bottlenecks. This represents a significant improvement toward a biosynthetic manufacturing route for psilocybin.
N-methylated tryptamines like psilocybin and DMT show promise as treatments for mental health disorders, driving interest in biosynthetic production. This work characterized two enzymes from tryptamine biosynthesis: TrpM, a tryptophan N-methyltransferase from Psilocybe serbica, and PsiD, a decarboxylase from the psilocybin pathway. TrpM was able to N-methylate 4-hydroxytryptophan, a non-native amino acid. However, incorporating TrpM into a functional psilocybin pathway was blocked because PsiD could not use N,N-dimethyl-4-hydroxytryptophan as a substrate under the tested conditions, despite acting on N-methylated and 4-hydroxylated tryptophan derivatives separately. These findings expand the known substrates for TrpM and PsiD, increasing the diversity of tryptamine biosynthetic products.