Collaborative Research: Harnessing synergism between biosurfactants and enzymes to enable efficient valorization of cellulose: towards a sustainable materials bioeconomy

合作研究：利用生物表面活性剂和酶之间的协同作用，实现纤维素的有效增值：迈向可持续的材料生物经济

• 批准号: 2210803
• 负责人: Tina Jeoh
• 金额: $ 30万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2210803&HistoricalAwards=false
• 关键词: Collaborative; Research; Harnessing; synergism; between

Cellulose is an abundant, renewable, and environmentally-sustainable resource that can be used to produce nanocellulose and value-added fuels and chemicals. As such, cellulose is an ideal feedstock for building a circular bioeconomy. To realize this potential, however, scalable and sustainable methods are needed to efficiently convert cellulose into nanocellulose. Current chemical and mechanical nanocellulose production processes are efficient but unsustainable, as they require high energy and water inputs, use toxic and corrosive solvents, and generate large amounts of greenhouse gas emissions and high-volume waste streams. Enzymatic processes enable sustainable nanocellulose production but suffer from low yields. Petroleum-derived surfactants are often added to enhance enzymatic bioconversion of cellulose, but selecting an ideal surfactant is not straightforward and incorporates non-renewable resources into the process. Saprophytic fungi decompose cellulosic biomass by secreting an enzyme-laden mixture that includes cellulases as well as naturally-occurring biosurfactants called hydrophobins. Hydrophobins have been implicated in enhancing enzymatic cellulose decomposition and, thus, offer a potential green alternative to petrochemical surfactants. However, the role hydrophobins play in enhancing cellulase activity on cellulose remains unclear. The goal of this project is to develop a scalable, environmentally-sustainable process for nanocellulose production by leveraging the surface activity of hydrophobins to improve cellulose deconstruction and modification. This research will result in new tools to improve enzymatic cellulose conversion, thereby enabling the cellulose-based circular bioeconomy.This project is motivated by the need for scalable and sustainable processes to convert cellulosic biomass into nanocellulose and value-added fuels and chemicals. The investigation focuses on improving the rate and extent of enzymatic hydrolysis of cellulose by incorporating hydrophobin biosurfactants, which appear to synergistically enhance cellulase performance. The project aims to elucidate the mechanisms of biosurfactant-enhanced enzyme-cellulose interfacial interactions such that the kinetics of cellulose hydrolysis and functionalized nanocellulose production can be controlled. The project has three specific aims. Aim 1 will examine how hydrophobins interact with cellulose to affect surface and material properties and determine how hydrophobins facilitate enzymatic interactions and turnover with cellulose. Aim 2 will build an understanding of how the evolutionary diversity of hydrophobins leads to differences in cellulose and enzyme adsorption. This knowledge will be used to engineer novel hydrophobins with improved interfacial interactions that increase nanocellulose production. Aim 3 will evaluate the integration of enzymes, hydrophobins, and cellulose to engineer ideal conditions for consolidated bioprocessing, considering both in vitro and cell-based systems using Trichoderma reesei as a host. Ultimately, this work will lead to new knowledge of how biological systems modify interfaces during cellulose deconstruction, which is key to developing enzymatic approaches for efficient nanocellulose production.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

纤维素是一种丰富、可再生且环境可持续的资源，可用于生产纳米纤维素以及增值燃料和化学品。因此，纤维素是建设循环生物经济的理想原料。然而，为了实现这一潜力，需要可扩展且可持续的方法来有效地将纤维素转化为纳米纤维素。目前的化学和机械纳米纤维素生产工艺虽然高效，但不可持续，因为它们需要大量的能源和水输入，使用有毒和腐蚀性溶剂，并产生大量温室气体排放和大量废物流。酶法可实现可持续的纳米纤维素生产，但产量较低。通常添加石油衍生的表面活性剂来增强纤维素的酶促生物转化，但选择理想的表面活性剂并不简单，并且将不可再生资源纳入该过程。腐生真菌通过分泌一种充满酶的混合物来分解纤维素生物质，该混合物包括纤维素酶以及称为疏水蛋白的天然生物表面活性剂。疏水蛋白与增强酶促纤维素分解有关，因此为石化表面活性剂提供了潜在的绿色替代品。然而，疏水蛋白在增强纤维素酶活性方面所起的作用仍不清楚。该项目的目标是通过利用疏水蛋白的表面活性来改善纤维素的解构和改性，开发一种可扩展、环境可持续的纳米纤维素生产工艺。这项研究将产生新的工具来改善酶促纤维素转化，从而实现基于纤维素的循环生物经济。该项目的动机是需要可扩展和可持续的工艺，将纤维素生物质转化为纳米纤维素和增值燃料和化学品。该研究的重点是通过掺入疏水蛋白生物表面活性剂来提高纤维素酶水解的速率和程度，这似乎可以协同增强纤维素酶的性能。该项目旨在阐明生物表面活性剂增强的酶-纤维素界面相互作用的机制，从而可以控制纤维素水解和功能化纳米纤维素生产的动力学。该项目有三个具体目标。目标 1 将检查疏水蛋白如何与纤维素相互作用以影响表面和材料特性，并确定疏水蛋白如何促进酶促相互作用和与纤维素的周转。目标 2 将了解疏水蛋白的进化多样性如何导致纤维素和酶吸附的差异。这些知识将用于设计新型疏水蛋白，改善界面相互作用，从而增加纳米纤维素的产量。目标 3 将评估酶、疏水蛋白和纤维素的整合，以设计整合生物加工的理想条件，同时考虑使用里氏木霉作为宿主的体外和细胞系统。最终，这项工作将带来关于生物系统如何在纤维素解构过程中改变界面的新知识，这是开发高效纳米纤维素生产酶促方法的关键。该奖项反映了 NSF 的法定使命，并通过使用基金会的知识进行评估，被认为值得支持。优点和更广泛的影响审查标准。