TY - JOUR

T1 - Photobiocatalysis by a Lytic Polysaccharide Monooxygenase Using Intermittent Illumination

AU - Blossom, Benedikt M.

AU - Russo, David A.

AU - Singh, Raushan K.

AU - Van Oort, Bart

AU - Keller, Malene B.

AU - Simonsen, Tor

AU - Perzon, Alixander

AU - Gamon, Luke F.

AU - Davies, Michael J.

AU - Cannella, David

AU - Croce, Roberta

AU - Jensen, Poul Erik

AU - Bjerrum, Morten J.

AU - Felby, Claus

PY - 2020

Y1 - 2020

N2 - Photobiocatalysis holds great promise toward the development of sustainable and environmentally friendly processes, harnessing light to drive biocatalytic reactions. However, photobiocatalysis at the interface of insoluble substrates, such as cellulose, has not been studied in much detail. In this context, the catalytic enhancement of lytic polysaccharide monooxygenases (LPMOs) by light is of great interest to the biorefinery field due to their capacity to oxidatively cleave such recalcitrant polysaccharides which can facilitate the degradation of lignocellulose. It has previously been reported that light-driven LPMO reactions have a huge catalytic potential, but effective continuous illumination in reactors may be challenging. Therefore, we investigated the impact of intermittent illumination. We show that illumination intervals as short as 1 s/min enable LPMO catalysis on phosphoric acid-swollen cellulose (PASC) to the same level as continuous illumination. Additionally, time-resolved measurements indicate that reductant depletion, and not enzyme inactivation, limits light-driven LPMO reactions. This study shows that a 60-fold reduction in illumination time enhances LPMO catalysis while protecting reaction elements, e.g., the reductant. Most importantly, the significant enhancement of LPMO catalysis with minimal and intermittent illumination is promising toward an application of photobiocatalytic depolymerization of lignocellulose where shading and light scattering minimize light availability and continuity.

AB - Photobiocatalysis holds great promise toward the development of sustainable and environmentally friendly processes, harnessing light to drive biocatalytic reactions. However, photobiocatalysis at the interface of insoluble substrates, such as cellulose, has not been studied in much detail. In this context, the catalytic enhancement of lytic polysaccharide monooxygenases (LPMOs) by light is of great interest to the biorefinery field due to their capacity to oxidatively cleave such recalcitrant polysaccharides which can facilitate the degradation of lignocellulose. It has previously been reported that light-driven LPMO reactions have a huge catalytic potential, but effective continuous illumination in reactors may be challenging. Therefore, we investigated the impact of intermittent illumination. We show that illumination intervals as short as 1 s/min enable LPMO catalysis on phosphoric acid-swollen cellulose (PASC) to the same level as continuous illumination. Additionally, time-resolved measurements indicate that reductant depletion, and not enzyme inactivation, limits light-driven LPMO reactions. This study shows that a 60-fold reduction in illumination time enhances LPMO catalysis while protecting reaction elements, e.g., the reductant. Most importantly, the significant enhancement of LPMO catalysis with minimal and intermittent illumination is promising toward an application of photobiocatalytic depolymerization of lignocellulose where shading and light scattering minimize light availability and continuity.

KW - Photobiocatalysis

KW - Lytic polysaccharide monooxygenases

KW - Cellulose oxidation

KW - Intermittent light

KW - Reactive oxygen species (ROS)

KW - Photosensitizer

KW - Chlorophyllin

KW - CELLULOSE

KW - COPPER

KW - DEGRADATION

KW - OXIDATION

KW - ENZYMES

U2 - 10.1021/acssuschemeng.0c00702

DO - 10.1021/acssuschemeng.0c00702

M3 - Journal article

VL - 8

SP - 9301

EP - 9310

JO - A C S Sustainable Chemistry & Engineering

JF - A C S Sustainable Chemistry & Engineering

SN - 2168-0485

IS - 25

ER -