Polysaccharide and Fructose Syrup Production using Glucosyltransferase Enzymes

Commercialization of chemicals and materials derived from bio-based sources requires finding opportunities that have the right balance between performance, cost, and sustainability.  A significant challenge using fermentation technology is the loss of carbon to CO2; carbon yields significantly lower than 50% are the norm, and these low yields have substantial implications on both the process economics and environmental footprint.  One approach to improve these metrics is to use enzymatic processes instead of microbial fermentations.

The production of engineered polysaccharides using glucosyltransferase enzymes is an example of a technology that allows for 100% of the carbon to be recovered as valuable products.  These enzymes convert sucrose into a polysaccharide comprising glucose while simultaneously generating an enriched fructose stream.  This method of producing fructose is also advantaged compared to the typical starch process.

Commercial fructose syrup products contain 42-55 wt% dry weight basis (DWB) fructose.  The 55 wt% DWB fructose stream cannot be produced directly and requires several chromatographic steps to achieve an intermediate stream containing 90+ wt% DWB fructose.  This high purity fructose stream is then back blended to achieve the right composition.  Overall, this incumbent process is extremely energy intensive due to the large amount of water evaporated in the chromatography process.  Comparatively, the glucosyltransferase approach outlined above directly generates a high purity fructose syrup containing 75+ wt% DWB fructose suitable for blending while completely avoiding chromatography and the associated evaporation requirements.  These glucosyltransferase based processes thus enable the production of new polysaccharide materials while simultaneously streamlining the production of fructose syrup.