SUMMARY

Many industrially-relevant enzymes are active, but are severely limited by thermodynamic, kinetic, or stability issues. A Tufts University investigator and their research team has developed an isomerization protocol using a novel biocatalyst to overcome thermodynamic issues in the conversion of galactose into tagatose. This protocol has demonstrated high yields and titers.

PROBLEM

Tagatose is a natural sugar with potential for use as an artificial sweetener because of its minimal effect on blood glucose and insulin. It is found in very small quantities in various fruits and vegetables, making extraction-based manufacturing expensive and time-consuming. Current conversion methods for Tagatose achieve low yields at high temperatures with high purification costs due to thermodynamically limited enzymes. Other commercially available natural sugars are difficult to use in baking and some have even been associated with health risks.

SOLUTION

This biocatalyst system is designed to protect thermodynamically limited enzymes through probiotic bacterial encapsulation. Importantly, the encapsulation has been optimized to avoid jeopardizing enzymatic activity and harness the natural preference of the bacteria to consume galactose and expel tagatose. The global diabetes crisis, rising relevance of prebiotics, and shifting consumer preference for all-natural foods positions tagatose perfectly for commercial development.

SUPPORTING EVIDENCE

In order to improve substrate exchange without harming the bacterial cell components, the research team tested the permeabilization effects of detergents and solvents. Sub-micellar concentration of a detergent called SDS resulted in the significant increase in whole-cell reactions to free-enzyme-like rates while circumventing the thermodynamic barrier to conversion (figure). The figure demonstrates an 85% conversion rate in the bacterial encapsulated enzymes at 50℃ in 48 hours. Overall, this biocatalytic system is able to achieve a higher conversation percentage with a higher product titer than which is currently described in literature.

Advantages

•       High-yield protocol

•       Anti-glycemic

•       Prebiotic

•       GRAS

Applications

•       Protocol applicable various sugars

•       Sugar substitute in baking

IP STATUS   Provisional patent application filed February 2020.

Licensing Contact

Emma Anderson
EmmaMarie.Anderson@tufts.edu