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Non-aqueous homogenous biocatalytic conversion of polysaccharides in ionic liquids using chemically modified glucosidase

Nature Chemistryvolume 10pages859865 (2018) | Download Citation

Abstract

The increasing requirement to produce platform chemicals and fuels from renewable sources means advances in biocatalysis are rapidly becoming a necessity. Biomass is widely used in nature as a source of energy and as chemical building blocks. However, recalcitrance towards traditional chemical processes and solvents provides a significant barrier to widespread utility. Here, by optimizing enzyme solubility in ionic liquids, we have discovered solvent-induced substrate promiscuity of glucosidase, demonstrating an unprecedented example of homogeneous enzyme bioprocessing of cellulose. Specifically, chemical modification of glucosidase for solubilization in ionic liquids can increase thermal stability to up to 137 °C, allowing for enzymatic activity 30 times greater than is possible in aqueous media. These results establish that through a synergistic combination of chemical biology (enzyme modification) and reaction engineering (solvent choice), the biocatalytic capability of enzymes can be intensified: a key step towards the full-scale deployment of industrial biocatalysis.

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Acknowledgements

The authors thank the EPSRC (Frontier Engineering Grant EP/K038648/1) for financial support. The authors also thank G. Siligardi, R. Hussain and T. Jaforvi at the Diamond Light Source for access to the B23 beamline, N. Terrill and A. Smith at the Diamond Light Source for access and support at the I22 beamline, W.-C. Tu for running HPLC samples and P. Carry for access to FTIR and dynamic light scattering.

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Affiliations

  1. Department of Chemical Engineering, Imperial College London, Exhibition Road, London, UK

    • Alex P. S. Brogan
    • , Liem Bui-Le
    •  & Jason P. Hallett

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Contributions

A.P.S.B. designed and performed the experiments, A.P.S.B. and J.P.H. wrote the manuscript, and L.B.-L. synthesized and characterized the ionic liquids. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Jason P. Hallett.

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DOI

https://doi.org/10.1038/s41557-018-0088-6