Production of steviol glycosides through whole cell biotransformation

Abstract

In various aspects and embodiments, the invention provides microbial cells and methods for producing advanced glycosylation products from lower glycosylated intermediates. The microbial cell expresses one or more UDP-dependent glycosyl transferase enzymes in the cytoplasm, for glycosylation of the intermediates. When incubating the microbial strain with a plant extract or fraction thereof comprising the intermediates, these glycosylated intermediates are available for further glycosylation by the cell, and the advanced glycosylation products can be recovered from the media and / or microbial cells.

Description

[0001] priority [0002] This application claims priority to and benefit of U.S. Provisional Application No. 62 / 698,617, filed July 16, 2018, which is hereby incorporated by reference in its entirety. Background technique [0003] Small molecule glycosyltransferases are encoded by large multigene families in the plant kingdom. These enzymes transfer sugars from nucleotide sugars to a broad range of secondary metabolites, thereby altering the physicochemical properties of receptor molecules. For example, steviol glycosides are a class of compounds found in the leaves of Stevia rebaudiana Bertoni, a perennial shrub of the Asteracae (Compositae) family native to certain regions of South America. Their structure is characterized by monobasic steviol, differing by the presence of carbohydrate residues at positions C13 and C19. They accumulate in the stevia leaf, constituting approximately 10% to 20% of the total dry weight. On a dry weight basis, the four major glycosides found ...

AI Technical Summary

Problems solved by technology

Although RebM is of great interest in the global food industry, its low penetration in stevia extracts requires innovative synthetic approaches

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