Example 10
As part of evaluating the feasibility of a yeast-based approach as a treatment to mitigate the effects of elevated concentrations of fructose in foods and beverages, several evolved clones obtained by adaptive evolution were tested for their ability of degrading fructose when present in food.
For this study, two evolved yeast strains obtained by adaptive evolution, G1_1A and G2_1A were tested for their ability to degrade dietary fructose. The testing of fructose consumption was started with yeast cells obtained from a culture initiated from a single colony on agar plates and grown in 15 mL of liquid YP medium in a 50-mL mini-bioreactor by incubation at 30° C. with an agitation of 225 rpm supplemented with 4% fructose. Cells were pelleted by centrifugation at 1000 rpm (Sorval, RT7) for 10 min at room temperature. Cell pellets were resuspended in 5 mL rodent diet (Teklad, Envigo) spiked with a solution of 10% fructose (=555 mM). Reactions were incubated at 37° C. to mimic human gastrointestinal temperature conditions. Aliquots of the reactions were taken at multiple time points and stored at −20° C. until fructose concentration determination using the colorimetric Fructose Assay Kit (Cat. No. EFRU-100; BioAssay Systems, Hayward, CA).
As shown in Table 12, the evolved clones were able to rapidly decrease fructose concentration when present in diet.
