Bio-based Production of a Novel Switchable Solvent

Emily Soon, Michael Chae and David C. Bressler.
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.

Switchable solvents are a novel class of chemicals characterized with a unique ability to reversibly switch specific physical properties in response to certain triggers. For instance, a low polarity solvent can be converted to one of high polarity and back to low polarity due to the presence or absence of the trigger. Switchable solvents have the potential for green use in industrial applications and could replace traditional methods for separating products from solvents or media, which can be expensive and/or energy-intensive. Moreover, because of their novel switchable properties these solvents can be recycled, thus reducing material usage. Currently, industrial application of switchable solvents is limited by commercial availability and difficulty and expense in producing. Hence there is a need for alternative means of producing switchable solvents. One alternative is the bio-based production of switchable solvents using biological conversions of Alberta feedstock. The purpose of this research is to engineer a microbial strain capable of producing a novel switchable solvent during fermentation. The production of the switchable solvent occurs by enzymatic conversion of the primary amine precursor to a tertiary amine that has been previously reported to display switchable properties.

A candidate enzyme with the potential to convert the precurosr to the target switchable solvent was identified. The DNA sequence encoding this enzyme was cloned into and expressed in Escherichia coli. The methylation activity of the purified enzyme was tested for its ability to form the switchable solvent from the precursor.