Biocatalytic valorisation of flower waste: Towards sustainable feedstock for fine chemical industry

你知道像印度这样的国家每天产生超过30万吨的花卉废料吗？想象一下，再利用花卉废料为化学工业制造高价值的起始材料！随着人们对资源利用和政府监管的认识不断提高，化工行业正在迅速认识到可持续制造的必要性。寻找石化原料（如生物质）的可持续替代品和使用资源高效技术（取代传统的间歇反应器）是两种迅速获得研究和行业关注的战略，以实现化学品的可持续生产。在这个双重目标项目中，我们将：（i）首次证明链霉菌作为生物催化剂的潜力，将花卉废物转化为高价值的化学品，（ii）研究连续反应器中的工艺放大。花是芳香和生物活性化合物的丰富来源，是食品、制药和化妆品工业的重要原料。目前，这些化合物要么从鲜花中获得，要么通过合成途径生产，从长远来看，这两种方法都不是可持续的解决方案。该项目将侧重于将萜烯醇（通常存在于花卉生物质中）转化为萜烯酯和甲基丙烯酸酯，这是食品，香料和聚合物工业的重要起始材料。生产这些化合物的现有技术的限制是：（i）由于传质限制而导致的长反应时间，（ii）由于产物抑制而导致的产物产率损失，和（iii）昂贵酶的有限的可重复使用性。链霉菌等微生物是解决与金属和金属有机催化剂（有毒、昂贵且容易受到催化剂中毒）相关的挑战的有吸引力的解决方案，并提供了进行化学转化的良性途径。链霉菌在自然环境中普遍存在，并分泌大量胞外酶用于溶解植物来源的聚合物。本计画的第一部分将首先探讨花卉废弃物中萜烯醇的生物催化转化反应机制。这涉及确定正确的反应条件，以最大限度地提高实验室规模的产品产率。该反应将进行使用自由和固定化链霉菌属。该项目的第二部分涉及应用在第一阶段开发的反应协议，以证明在微通道（MC）和转盘反应器（SDR）的规模。这些反应器配置由于其实现快速反应的能力而迅速获得行业关注，这归因于增加的传质、小的化学品库存、可扩展性和固有的安全性。该项目将首次测试MC和SDR在全细胞催化反应系统中的潜力。这在很大程度上是一个实验项目，在分析和表征技术，生物反应器开发和优化方面有充足的培训机会。该项目还允许通过参加研究小组会议、在研讨会和会议上发言、行业和公众参与来发展额外的技能。

Did you know countries like India produce more than 300 kilotons of flower waste every day? Imagine re-using the flower waste to make high value starting materials for the chemical industry! With an increasing awareness about resource use and government regulation, chemical industries are fast realising the need for sustainable manufacturing. Identifying sustainable alternatives for petrochemical feedstock (like biomass) and using resource efficient technologies (to replace the conventional batch reactor) are two strategies which are fast gaining research and industry attention to enable sustainable production of chemicals. In this two-fold objective project we will: (i) demonstrate for the first time the potential of Streptomyces sp. as a biocatalyst for valorisation of flower waste into high value chemicals and (ii) investigate process scale-up in continuous reactors. Flowers are an abundant source of aromatic and biologically active compounds, which are important raw materials for the food, pharmaceutical and the cosmetic industry. Currently, these compounds are either obtained from fresh flowers or produced using synthetic routes, both of which are not sustainable solutions in the long run. This project will focus on the conversion of terpene alcohols (commonly present in flower biomass) into terpene esters and methacrylate, which are important starting materials for food, fragrance and polymer industries. The limitations of current state-of-the-art to produce these compounds are: (i) long reaction times due to mass transfer limitations, (ii) loss in product yield due to product inhibition and (iii) limited reusability of expensive enzymes. Microbes like Streptomyces sp. are an attractive solution to challenges associated with metal and metal organic catalysts (toxic, expensive and susceptible to catalyst poisoning) and provide a benign pathway to carry out chemical transformations. Streptomyces sp. are ubiquitous in the natural environment and excrete a large number of extracellular enzymes for the solubilisation of plant-derived polymers. The first part of this project will first focus on investigating the reaction mechanism for biocatalytic conversion of terpene alcohols derived from flower waste. This involves identifying the right reaction conditions to maximise the product yield on the bench scale. This reaction will be carried out using both free and immobilised Streptomyces sp. The second part of the project involves applying the reaction protocol developed in the first stage to demonstrate scale-up in micro-channel (MC) and spinning disc reactors (SDR). These reactor configurations are fast gaining industry attention for their ability to achieve fast reactions due to increased mass transfer, small chemical inventory, scalability and inherent safety. This project for the first time will test the potential of the MC and SDR for whole cell catalysed reaction systems. This is largely an experimental project with ample training opportunities in analytical and characterisation techniques, bioreactor development and optimisation. The project also allows for additional skills development through participation in research group meetings, presentation in seminars and conferences, industry and public engagement.