RT Journal Article SR Electronic T1 Complete absence of thebaine biosynthesis under home-brew fermentation conditions JF bioRxiv FD Cold Spring Harbor Laboratory SP 024299 DO 10.1101/024299 A1 Drew Endy A1 Stephanie Galanie A1 Christina D. Smolke YR 2015 UL http://biorxiv.org/content/early/2015/08/13/024299.abstract AB Yeast-based biosynthesis of medicinal compounds traditionally derived from plant materials is improving. Both concerns and hopes exist for the possibility that individual small volume batch fermentations could provide distributed and independent access to a diversity of compounds some of which are now abused, illegal, or unavailable to many who need for genuine medical purposes. However, there are differences between industrial bioreactors and ‘home-brew’ fermentation. We used engineered yeast that make thebaine, a morphinan opiate, to quantify if differences in fermentation conditions impact biosynthesis yields. We used yeast that make an English ale as a positive fermentation control. We observed no production of thebaine and miniscule amounts of reticuline, an upstream biosynthetic intermediate, in home-brew fermentations; the positive control was palatable. We suggest that additional technical challenges, some of which are unknown and likely unrelated to optimized production in large-volume bioreactors, would need to be addressed for engineered yeast to ever realize home-brew biosynthesis of medicinal opiates at meaningful yields.