A modular biosynthetic production platform for psilocybin was developed in the model microbe Escherichia coli. Multiple genetic optimization techniques improved psilocybin titer by 32-fold. Further fermentation optimization in a fed-batch study achieved a production titer of 1.16 g/L of psilocybin, the highest titer reported from a recombinant organism to date. This work demonstrates progress toward the industrial bioproduction of psilocybin for clinical use.
Bacterial production of psilocybin and 13 related compounds was achieved by adding the enzyme PsiH to the existing biosynthesis pathway. Testing 49 different indole derivatives revealed that the pathway enzymes accept many substrates, enabling the creation of a library of new drug candidates for mental health treatment.
Psilocybin and other psychedelic compounds are being studied for therapeutic use, but little is known about norbaeocystin, a pathway intermediate, due to difficulties obtaining it. Researchers developed a new E. coli platform to produce gram-scale amounts of norbaeocystin, finding that even minor genetic changes required reoptimization of production. In vivo tests on Long-Evans rats showed a dose response to psilocybin, but norbaeocystin did not elicit any pharmacological response, suggesting it and its metabolites may not strongly bind to the serotonin 2A receptor. This work enables future studies of norbaeocystin in animal models and supports the safety of using cell broth as a drug delivery vehicle.
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.