An ATP-free in vitro synthetic enzymatic biosystem facilitating one-pot stoichiometric conversion of starch to mannitol

• Published in: Applied microbiology and biotechnology Vol. 105; no. 5; pp. 1913 - 1924
• Main Authors: Wei, Xinlei, Li, Qiangzi, Hu, Congcong, You, Chun
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-03-2021; Springer; Springer Nature B.V
• Subjects: Alcohols; ATP; Biomedical and Life Sciences; Biotechnological Products and Process; Biotechnology; Conversion; Design; Enzymes; Food industry; Industrial applications; Life Sciences; Low cost; Maltodextrin; Mannitol; Microbial Genetics and Genomics; Microbiology; Pharmaceutical industry; Pipeline design; Polyols; Production processes; Prospective Studies; Starch; Stoichiometry; Substrates; Sugar; Sugar Alcohols; Synthesis; China; D-Mannitol; Reaction modules; Cascade biocatalysis; Maltodextrin; In vitro synthetic biology
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-021-11154-9

D-Mannitol (hereinafter as mannitol) is a six-carbon sugar alcohol with diverse applications in food and pharmaceutical industries. To overcome the drawbacks of the chemical hydrogenation method commonly used for mannitol production at present, there is a need to search for novel prospective mannitol production strategies that are of high yield and low cost. In this study, we present a novel approach for the stoichiometric synthesis of mannitol via an in vitro synthetic enzymatic biosystem using the low-cost starch as substrate. By dividing the overall reaction pathway into three modules which could be executed sequentially in one pot, our design aimed at the stoichiometric conversion of starch-based materials into mannitol in an ATP-independent and cofactor-balanced manner. At optimized conditions, high product yields of around 95-98% were achieved using both 10 g/L and 50 g/L maltodextrin as substrate, indicating the potential of our designed system for industrial applications. This study not only provides a high-efficient strategy for the synthesis of mannitol but also expands the product scope of sugar alcohols by the in vitro synthetic enzymatic biosystems using low-cost starch-based materials as the input.
Key points
• We described a design-build-test-learn pipeline to construct in vitro biosystems.
• The designed system comprised six key enzymes and another three enzymes.
• The system converted maltodextrin stoichiometrically to mannitol in one pot.