Bug-Busting Spandex: Biodegrading Textile Blends for Molecular Recycling

消灭昆虫的氨纶：用于分子回收的生物降解纺织品混合物

• 批准号: BB/X011348/1
• 负责人: Helen Hailes
• 金额: $ 38.69万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FX011348%2F1
• 关键词: Bug; Busting; Spandex; Biodegrading; Textile

Waste textiles are a major issue worldwide and recent reports have highlighted that Britons throw away ~ 3 kg textiles each year. While some waste clothing (~10%) is resold or exported, nearly 50% ends up in landfill in the UK which is a missed recycling opportunity. The global polyester fibre market was $74 billion in 2020 and is projected to rise to $124 billion by 2027. Polyester fibre is made from processed polyethylene terephthalate (PET), including virgin fibres, and more recently recycled PET. Spandex, also known as Lycra or Elastane, is an important elastane fibre with production levels of 1 million tonnes/year. It is used in many stretchy fabrics such as activewear as a textile blend with polyesters (e.g. ratio Spandex:PET, 15:85 or less). Such blended textiles are particularly challenging to recycle into useful materials due to the complex structure, however biotechnological approaches have the potential to degrade the polymers into fragments or small molecules for recycling or upgrading into other polymers or materials. This project aims to identify and develop enzymes for the breakdown of polyester/Spandex fabric blends and to recycle the small molecule monomers into either new polymers, for use as a feedstock for biopolymer synthesis, or as a drug precursor. This 'bug-busting' strategy for Spandex textile blends will provide routes to tackle a major problematic textile waste stream. A particular challenge of Spandex is their combination with other textiles into fabric blends, and the carbamate bonds which are hard to hydrolyse under mild conditions. While there have been significant developments recently in generating productive enzymes to break down plastic PET bottles, there has been little work carried on the breakdown of PET polyesters in textiles. There are also currently very few enzymes that cleave the carbamate bond that have been characterized.Several strategies to obtain productive degrading enzymes for polyester/Spandex blends are proposed. Crucial to the rapid success of enzyme discovery and screening will be suitable assays and for this we will synthesise substrates for the development of chromogenic high throughput assays on an automated platform and for subsequent screening on an analytical HPLC machine. The biodegradation of polyesters will be investigated using current in-house PETases and esterases, and available PETases, together with the use of mechanoenzymatic reaction conditions and ionic liquids to enhance textile/enzyme interactions. Then the Spandex biodegradation will be explored via the identification of enzymes that can break down the carbamate bond. This will be through the development of microbial consortia/bacteria from enrichment experiments in hotbins set up two years ago, assays, DNA sequencing and enzyme identification. Also, informatics approaches and the use of databases, and metagenomic strategies including our metagenomics database. The polyester and Spandex degrading enzymes will then be combined and optimised using enzyme mutagenesis approaches and high throughput automated screening platforms. Using the best combination of enzymes, procedures will be tested to isolate the key aromatic acid and amine fragments, while the remaining soft segment components can potentially be used as a carbon feedstock for bioplastic production. A route to enhance the value of the amine fragment will also be explored using in house oxidative enzymes. Throughout the project and through links to the UCL Plastic Waste Innovation Hub we will assess the social, economic, and environmental impact of the technologies developed and gather the data for a life cycle analysis.

废弃纺织品是世界范围内的一个主要问题，最近的报告强调英国人每年丢弃约 3 公斤纺织品。虽然一些废旧衣物（约 10%）被转售或出口，但近 50% 最终进入英国的垃圾填埋场，从而错失了回收机会。 2020 年，全球聚酯纤维市场规模为 740 亿美元，预计到 2027 年将增至 1240 亿美元。聚酯纤维由经过加工的聚对苯二甲酸乙二醇酯 (PET) 制成，包括原生纤维和最近回收的 PET。氨纶，也称为莱卡或弹性纤维，是一种重要的弹性纤维，产量为 100 万吨/年。它被用于许多弹力织物，例如运动服，作为与聚酯的纺织混合物（例如氨纶：聚酯纤维的比例为 15:85 或更低）。由于结构复杂，这种混合纺织品回收成有用材料特别具有挑战性，然而生物技术方法有可能将聚合物降解成碎片或小分子，以便回收或升级成其他聚合物或材料。该项目旨在识别和开发用于分解聚酯/氨纶织物混合物的酶，并将小分子单体回收成新的聚合物，用作生物聚合物合成的原料，或用作药物前体。这种针对氨纶纺织混合物的“除虫”策略将为解决主要的纺织废物流问题提供途径。氨纶的一个特殊挑战是它们与其他纺织品组合成织物混纺物，以及在温和条件下难以水解的氨基甲酸酯键。虽然最近在生产用于分解塑料 PET 瓶的生产性酶方面取得了重大进展，但在分解纺织品中的 PET 聚酯方面开展的工作却很少。目前已经表征的能够裂解氨基甲酸酯键的酶也很少。提出了几种获得用于聚酯/氨纶共混物的高效降解酶的策略。酶发现和筛选的快速成功至关重要的是合适的测定，为此，我们将合成底物，用于在自动化平台上开发显色高通量测定，并在分析型 HPLC 机器上进行后续筛选。将使用当前的内部 PETase 和酯酶以及可用的 PETase，以及使用机械酶反应条件和离子液体来研究聚酯的生物降解，以增强纺织品/酶的相互作用。然后，将通过鉴定可以分解氨基甲酸酯键的酶来探索氨纶的生物降解。这将通过两年前建立的热箱中的富集实验、化验、DNA 测序和酶鉴定来开发微生物群落/细菌。此外，信息学方法和数据库的使用，以及宏基因组策略，包括我们的宏基因组数据库。然后，将使用酶诱变方法和高通量自动筛选平台对聚酯和氨纶降解酶进行组合和优化。使用最佳的酶组合，将测试分离关键芳香酸和胺片段的程序，而其余的软链段成分则有可能用作生物塑料生产的碳原料。还将探索使用内部氧化酶来提高胺片段价值的途径。在整个项目中，通过与伦敦大学学院塑料废物创新中心的链接，我们将评估所开发技术的社会、经济和环境影响，并收集数据进行生命周期分析。