According to new studies by researchers from Concordia University in Montreal and the
University of California, Berkeley, yeast can be engineered to convert sugar to alkaloids — plant-derived compounds such as codeine and morphine, naturally produced in the opium poppy. 

Thanks to research by teams led by Vincent Martin at Concordia and John Dueber at UC Berkeley, the key steps needed to make yeast able to produce alkaloids from inexpensive sugar have been identified. The research was made possible in part by funding from Genome Canada and Génome Québec.

To learn more: http://www.nature.com/nchembio/journal/vaop/ncurrent/full/nchembio.1816.html