Made in yeast

Scientists have developed a new way to produce a group of plant compounds, that include nicotine and codeine, in yeast according to a study published online this week in Nature Chemical Biology.

These molecules, known as alkaloids, are often too complex to produce chemically and are difficult to extract from natural sources. This research therefore provides access to many previously unattainable molecules that could have therapeutic potential.

Kristy Hawkins and Christina Smolke inserted a series of plant enzymes into yeast, enabling them to make reticuline, a major precursor for alkaloid molecules. By mixing and matching additional plant and human enzymes, the authors generated yeast that produced precursors of sanguinarine ? a toothpaste additive with antiplaque properties ? berberine ? an antibiotic ? and morphine ? a pain reliever. They also used an enzyme ‘tuning’ strategy to maximize alkaloid formation and minimize resource costs to the yeast.

This engineered yeast will facilitate the creation of new alkaloids that do not exist in nature and may also provide the foundation for an alternative approach to commercial production of alkaloid therapeutics.