催化学报

催化学报 ›› 2025, Vol. 72: 84-94.DOI: 10.1016/S1872-2067(25)64656-0

• 论文 • 上一篇    下一篇

天然酶-纳米酶仿生杂合体系促进木质素高效解聚

王鑫颖a,1, 田庆b,1, 陈耀b, 李爱朋a,*(), 张连兵b, 张明明c, 李昌志d,*(), 费强a,*()   

  1. a西安交通大学化学工程与技术学院, 陕西西安 710049
    b西北工业大学生命学院, 陕西西安 710072
    c西安交通大学材料科学与工程学院, 陕西西安 710049
    d中国科学院大连化学物理研究所, 辽宁大连 116023
  • 收稿日期:2024-12-13 接受日期:2025-02-15 出版日期:2025-05-18 发布日期:2025-05-20
  • 通讯作者: *电子信箱: feiqiang@xjtu.edu.cn (费强),licz@dicp.ac.cn (李昌志),liaipeng@xjtu.edu.cn (李爱朋).
  • 作者简介:1共同第一作者.
  • 基金资助:
    国家重点研发计划(2023YFC3403500);陕西省重点研发计划(2024NC-YBXM-226);中国博士后科学基金(2023M732780);高等学校学科创新引智计划(B23025);陕西高校青年创新团队

A de novo biomimetic enzyme-nanozyme hybrid system for advancing lignin valorization

Xinying Wanga,1, Qing Tianb,1, Yao Chenb, Aipeng Lia,*(), Lianbing Zhangb, Mingming Zhangc, Changzhi Lid,*(), Qiang Feia,*()   

  1. aSchool of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China
    bSchool of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, China
    cSchool of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China
    dCAS Key Laboratory of Science and Technology on Applied Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
  • Received:2024-12-13 Accepted:2025-02-15 Online:2025-05-18 Published:2025-05-20
  • Contact: *E-mail: feiqiang@xjtu.edu.cn (Q. Fei), licz@dicp.ac.cn (C. Li), liaipeng@xjtu.edu.cn (A. Li).
  • About author:1 Contributed equally to this work.
  • Supported by:
    National Key R&D Programs of China(2023YFC3403500);Key Research and Development Program of Shaanxi Province(2024NC-YBXM-226);China Postdoctoral Science Foundation(2023M732780);Higher Education Institution Academic Discipline Innovation and Talent Introduction Plan(B23025);Youth Innovation Team of Shaanxi Universities

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摘要：

木质素作为储量丰富的可再生天然芳香聚合物, 是高值芳香化合物合成的潜在原料. 遗憾的是, 由于结构的复杂性和异质性, 实现其定向降解为芳香小分子仍极具挑战. 自然界中, 木质素的降解常由多种天然酶协同完成, 具有反应条件温和、环境友好和选择性高等优势. 受此启发, 构建体外多酶体系成为实现木质素定向降解的重要途径. 然而, 天然酶构成的体外多酶体系的催化性能常不尽人意. 究其原因, 木质素降解酶的蛋白质特性, 如电荷状态、亲疏水性和尺寸大小可能会限制它们对复杂木质素特定区域的可及性. 纳米酶是具有类酶活性的纳米材料, 具有不同于蛋白质的理化性质. 因此, 天然酶和纳米酶的杂合有望实现功能互补, 促进木质素的降解甚至定向降解.

λ-MnO2纳米酶具有类漆酶活性, 而漆酶是自然界中重要的木质素降解酶. 此外, λ-MnO2纳米酶独特的理化性质, 如丰富的表面氧空位和稳定的金属-载体相互作用赋予了它强大的催化能力. 鉴于此, 本文通过简单的物理混合, 构建了一种由枯草芽孢杆菌漆酶CotA和λ-MnO2纳米酶组成的天然酶-纳米酶仿生杂合体系. 该杂合体系能够在温和条件下实现木质素的降解, 漆酶CotA和λ-MnO2纳米酶表现出显著的协同效应, 杂合体系木质素降解率达到25.15%, 较仅含有漆酶CotA(15.32%)或λ-MnO2纳米酶(14.90%)的单一催化剂体系分别提高了64.2%和68.8%. 值得注意的是, 杂合体系中芳香小分子产物的比例达到48%, 分别比漆酶CotA和λ-MnO2纳米酶的单一催化剂体系高41.2%和118.2%. 产物图谱分析和木质素结构表征发现, 杂合体系中芳香族化合物比例的显著提升可能受益于漆酶CotA介导的甲氧基化反应. 漆酶CotA介导的甲氧基化反应使得芳香小分子的空间位阻和电子特性发生改变, 限制了甲氧基化的芳香小分子进入λ-MnO2纳米酶的活性位点, 进而导致λ-MnO2纳米酶介导的开环反应受阻, 使得CotA+λ-MnO2杂合体系中保留了较高比例的芳香小分子化合物. 此外, 电子顺磁共振分析表明, 杂合体系中的羟基自由基(•OH)和超氧自由基(•O2-)的信号强度显著高于单一催化剂体系. 其中, 杂合体系中•OH的相对含量分别是漆酶CotA和λ-MnO2纳米酶单一催化剂体系的2.1倍和1.4倍, 而杂合体系中•O2-的相对含量分别比漆酶CotA和λ-MnO2纳米酶单一催化剂体系高1.4倍和2.2倍. 这表明天然酶与纳米酶对杂合体系中自由基的产生存在显著的协同效应, 为杂合体系中木质素降解率的提高提供了依据.

综上, 本文成功开发了一种由天然酶和纳米酶组成的仿生杂合体系, 该体系能够在温和条件下实现木质素的降解, 获得较高比例的芳香小分子化合物, 展示了天然酶-纳米酶杂合体系在木质素定向降解中的应用潜力. 在此基础上, 通过整合更多不同性质的天然酶和纳米酶, 开发更高效、更具针对性的杂合体系, 有望进一步提高木质素的降解效率, 精准控制芳香族产物的生成, 推动木质素高值化利用领域的发展.

关键词: 木质素, 仿生杂合体系, 高值化, 纳米酶, 天然酶

Abstract:

Directed degradation of abundant renewable lignin into small aromatic compounds is crucial for lignin valorization but challenging. The degradation of lignin in natural environments typically involves multienzyme synergy. However, the proteinaceous characteristics of lignin-degrading enzymes restrict their accessibility to certain regions of intricate lignin, resulting in the multienzyme systems being unable to fully demonstrate their effectiveness. Herein, a de novo biomimetic enzyme-nanozyme hybrid system was constructed by combining λ-MnO2 nanozyme with laccase CotA from Bacillus subtilis, aimed at facilitating lignin degradation under mild conditions. The lignin degradation rate of the CotA + λ-MnO2 hybrid system was determined to be 25.15%, which was much higher than those of the lignin degradation systems with only laccase CotA (15.32%) or λ-MnO2 nanozyme (14.90%). Notably, the proportion of aromatic chemicals in the products derived from the hybrid system reached as much as 48%, which was 41.2% and 118.2% higher than those of the CotA- and λ-MnO2-catalyzed systems, respectively. Analysis of products mapping and lignin structure changes suggested that the higher proportion of aromatic compounds in the CotA + λ-MnO₂ hybrid system was more likely to benefit from the laccase-mediated methoxylation. Moreover, electron paramagnetic resonance analysis indicated that the intensity and kind of free radicals such as •OH and •O2- are closely linked to the degradation rate and reaction type. This work is the inaugural application of an enzyme-nanozyme hybrid system for lignin degradation, demonstrating the potential of the synergistic interaction between enzyme and nanozyme in the directed degradation of lignin.

Key words: Lignin, Biomimetic hybrid, Valorization, Nanozyme, Natural enzyme