Successful Engineering of an Enzyme for the Biosynthesis of Natural Stevia-Based Sweeteners

January 10, 2025

A breakthrough in enhancing the accumulation of high-value sweetening compounds in plant

A collaborative research team from the University of Toyama, the RIKEN CSRS, Suntory Global Innovation Center, and Osaka University has made a significant advancement in the biosynthesis of rare stevia-derived sweeteners, Rebaudioside D (Reb D) and Rebaudioside M (Reb M). By introducing a single amino acid substitution (V155T) in the UGT91D2 enzyme, they successfully increased the accumulation of these compounds tenfold, representing a major step toward their efficient and sustainable production.

Stevia, a herbaceous plant of the Asteraceae family, naturally synthesizes Reb D and Reb M, which are highly valued for their superior sweetness and desirable taste profile. However, the limited enzymatic activity of UGT91D2 has constrained their accumulation. In this study, researchers enhanced UGT91D2 by replacing valine at position 155 with threonine and introduced the modified enzyme into plant cells. This modification led to a substantial increase in Reb D and Reb M levels.

Moving forward, the research team will focus on cultivating stevia plants carrying the V155T mutation, with the goal of developing new cultivars capable of producing these rare sweeteners more efficiently. This achievement paves the way for future advancements in the sustainable production of high-value natural sweeteners.

Original article

Journal of Agricultural and Food Chemistry　doi: 10.1021/acs.jafc.4c09392

T. Shoji, Y. Tanaka, Y. Nakashima, E. Mizohata, M. Komaki, S. Sugawara, J. Takaya, K. Yonekura-Sakakibara, H. Morita, K. Saito, T. Hirai,

"Enhanced Production of Rebaudioside D and Rebaudioside M through V155T Substitution in the Glycosyltransferase UGT91D2 from Stevia rebaudiana".

Contact

Tsubasa Shoji
Senior Visiting Scientist
Metabolomics Research Group