Bacterial lignin degradation: characterization and biocatalytic applications

细菌木质素降解：表征和生物催化应用

• 批准号: RGPIN-2018-04867
• 负责人: Eltis, Lindsay
• 金额: $ 8.45万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761026
• 关键词: Bacterial; lignin; degradation; characterization; biocatalytic

Bacteria are responsible for most of the degradation of natural and human-made compounds in the biosphere. This degradation constitutes an essential link in the global carbon cycle and is critical to sustaining life on our planet. Bacterial degradation activities also represent a rich, barely tapped source of biocatalysts to sustain the emerging global bioeconomy. Over the past two decades, my NSERC-funded research program has provided novel insights into the function of bacterial enzymes involved in the degradation of aromatic compounds and pollutants as well as into how these enzymes are regulated. Over the next five years, I will focus my program on enzymes that degrade lignin, a complex aromatic polymer that comprises about 25% of the land-based biomass. Lignin occurs in tight association with cellulose and hemicellulose to form the strong, rigid structure that is very resistant to degradation. Deconstructing this lignocellulose is critical to using woody biomass as a renewable source of chemicals, materials and other bioproducts. While fungal enzymes that degrade lignin have been studied for years, bacterial lignin-degrading enzymes have been largely overlooked despite being more amenable for industrial processes. My research will focus on two types of bacterial enzymes that: (a) breakdown the polymeric lignin; and (b) degrade the lignin depolymerization products. These enzymes represent important classes of metal-containing enzymes that are not well understood. The proposed research will increase our understanding of what these enzymes do and how they do it. This will in turn provide fundamental insights into the molecular mechanism of important biological processes as well as how Nature uses metals to catalyze these processes. The knowledge gained will also facilitate the engineering of enzymes and bacteria for biotechnological applications. More particularly, it will help in the design of biocatalysts to transform low-value lignin into high-value materials, such lubricants, cosmetics and bioplastics. The research objectives will be achieved using an interdisciplinary approach involving a variety of cutting-edge techniques. The research will benefit from a number of tools and approaches developed in the Eltis lab. Finally, the research program provides trainees with a wide range of skills, preparing them for fulfilling careers in academia, industry and government.

细菌是生物圈中天然和人造化合物大部分降解的原因。这种退化构成了全球碳循环的重要环节，对于维持地球上的生命至关重要。细菌降解活动也是一种丰富的、几乎未被开发的生物催化剂来源，可以维持新兴的全球生物经济。在过去的二十年中，我的 NSERC 资助的研究项目为参与芳香族化合物和污染物降解的细菌酶的功能以及这些酶的调节方式提供了新的见解。在接下来的五年中，我将把我的项目重点放在降解木质素的酶上，木质素是一种复杂的芳香族聚合物，约占陆地生物质的 25%。木质素与纤维素和半纤维素紧密结合，形成坚固、刚性的结构，非常耐降解。解构这种木质纤维素对于使用木质生物质作为化学品、材料和其他生物产品的可再生来源至关重要。虽然降解木质素的真菌酶已被研究多年，但细菌木质素降解酶尽管更适合工业过程，但在很大程度上被忽视。我的研究将集中于两种类型的细菌酶：（a）分解聚合木质素； (b)降解木质素解聚产物。这些酶代表了尚未被充分了解的重要的含金属酶类别。拟议的研究将增加我们对这些酶的作用以及它们如何作用的理解。这反过来将为重要生物过程的分子机制以及大自然如何利用金属催化这些过程提供基础见解。获得的知识还将促进用于生物技术应用的酶和细菌的工程设计。更具体地说，它将有助于设计生物催化剂，将低价值木质素转化为高价值材料，如润滑剂、化妆品和生物塑料。研究目标将通过涉及各种尖端技术的跨学科方法来实现。该研究将受益于 Eltis 实验室开发的许多工具和方法。最后，该研究项目为学员提供了广泛的技能，为他们在学术界、工业界和政府中实现职业生涯做好准备。