Engineered Biofilm Catalysts

从历史上看，生物膜主要被认为是有问题的；相关的感染，龋齿，海洋和反应堆污垢和减少传热。在它们的自然环境中，单个浮游细胞有在表面和界面聚集在一起的倾向。在这些簇中，它们通过分泌细胞外聚合物质（EPS）来保护自己免受环境和化学胁迫，EPS是一种保护性和粘性的多糖基质。这种EPS为生物膜提供了一定程度的保护，以抵御极端的pH值，温度或引入单个细胞无法耐受的有机溶剂。在目前寻找越来越绿色的方法来合成精细化学品和药品的全球气候中，人们对采用生物转化越来越感兴趣：利用细胞生产有用的产品。尽管这种策略能够生成对映异构纯化合物，减少合成路线中的步骤，并有可能消除对环境有害的催化剂、溶剂和试剂，但由于单个细胞通常无法忍受所需的极端条件，它们的使用存在问题。本研究利用生物膜制备高活性工程生物膜催化剂（EBC）。这是一个新的领域，因为生物膜在生物转化中的使用主要局限于废水处理和生物修复，通常由混合微生物群落称为财团。利用生物膜合成化合物的报道少之又少，工业上以这种方式生成的化合物的清单比简单的化合物如乙酸、乙醇、丁醇、2,3-丁二醇、乳酸、富马酸和琥珀酸更广泛。这一跨学科的建议提出了一种新的方法来开发和利用工程生物膜催化剂（EBC），用于与精细化工和制药工业相关的生物转化。最近，我们展示了一种工程生物膜催化剂（EBC）的产生和利用。固定的EBC不仅表现出前所未有的稳定性，而且被证明是比自由细胞更好的催化剂。由于EBC是人工生成的，因此设计其微观结构的空间相当大。我们建议探讨EBC在催化中的一般应用，并研究其微观结构和基因表达与催化活性的关系。我们将使用流动化学的EBC来生成生物转化的原型EBC反应器，作为未来工业开发的范例。

Historically, biofilms are predominantly perceived as problematic; associated with infections, dental caries, marine and reactor fouling and reduction in heat transfer. In their natural environment individual planktonic cells have the tendency to cluster together at surfaces and interfaces. Within these clusters they protect themselves from environmental and chemical stress by secreting extracellular polymeric substances (EPS) a protective and adhesive polysaccharide matrix. This EPS gives the biofilm a degree of protection against extremes of pH, temperature or the introduction of organic solvents which cannot be tolerated by individual cells. In the current global climate of searching for increasingly green approaches to the synthesis of fine chemicals and pharmaceuticals there is a growing interest in employing biotransformations: using cells to produce useful products. Although such a strategy enables the generation of enantiomerically pure compounds, the reduction of steps in a synthetic route and the possibility of eliminating environmentally detrimental catalysts, solvents and reagents, their use is problematic due to the fact that individual cells cannot in general tolerate the extreme conditions required. In this research we exploit biofilms to produce highly active Engineered Biofilm Catalysts (EBC). This is a new area as the use of biofilms in biotransformations has been largely confined to wastewater treatment and bioremediation generally by mixed microbial communities referred to as consortia. Reports of the use of biofilms for synthesis of compounds are few and far between, industrially the list of compounds generated in such a manner is little more extensive than simple compounds such as acetic acid, ethanol, butanol, 2,3-butanediol, lactic acid, fumaric acid, and succinic acid. This interdisciplinary proposal presents a novel methodology for the development and exploitation of engineered biofilm catalysts (EBC) for biotransformations relevant to the fine chemicals and pharmaceutical industries. Recently we have demonstrated the generation and utilisation of an Engineered Biofilm Catalyst (EBC). The immobilised EBC not only demonstrated unprecedented stability but proved to be a strikingly better catalyst than the free cells. As the EBC is artificially generated there is considerable scope to engineer its microstructure. We propose to explore the general application of EBC to catalysis as well as to investigate how microstructure and gene expression relate to catalytic activity. We will employ EBC using flow chemistry to generate a prototype EBC reactor for biotransformations as an exemplar for future industrial exploitation.