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.

中文翻译：

---

间歇性照明的溶胞多糖单加氧酶的光生物催化。

光生物催化在发展可持续和环境友好的过程方面具有广阔的前景，利用光来驱动生物催化反应。然而，尚未对在不溶性底物如纤维素的界面处的光生物催化进行详细研究。在这种情况下，由于光催化溶解性多糖单加氧酶（LPMOs）氧化裂解这种可促进木质纤维素降解的难降解多糖的能力，在生物炼制领域引起了极大的兴趣。以前已经报道过光驱动的LPMO反应具有巨大的催化潜力，但是在反应器中进行有效的连续照明可能具有挑战性。因此，我们研究了间歇照明的影响。我们表明，短至1 s / min的照明间隔使LPMO对磷酸溶胀的纤维素（PASC）的催化作用达到与连续照明相同的水平。此外，时间分辨的测量结果表明，还原剂的消耗（而不是酶的失活）限制了光驱动的LPMO反应。这项研究表明，照明时间减少60倍可增强LPMO催化，同时保护反应元素（如还原剂）。最重要的是，以最小和间歇的照明显着增强LPMO催化，有望在木质素纤维素的光生物催化解聚中得到应用，其中遮光和光散射将光的可用性和连续性降至最低。时间分辨的测量结果表明，还原剂的消耗而不是酶的失活限制了光驱动的LPMO反应。这项研究表明，照明时间减少60倍可增强LPMO催化，同时保护反应元素（如还原剂）。最重要的是，以最小和间歇的照明显着增强LPMO催化，有望在木质素纤维素的光生物催化解聚中得到应用，其中遮光和光散射将光的可用性和连续性降至最低。时间分辨的测量结果表明，还原剂的消耗而不是酶的失活限制了光驱动的LPMO反应。这项研究表明，照明时间减少60倍可增强LPMO催化，同时保护反应元素（如还原剂）。最重要的是，以最小和间歇的照明显着增强LPMO催化，有望在木质素纤维素的光生物催化解聚中得到应用，其中遮光和光散射将光的可用性和连续性降至最低。