Exploring the biotechnological potential of the UbiD (de)carboxylase family: novel biochemistry for renewable commodity chemicals

预计化石石油资源将枯竭，继续使用化石石油将直接造成全球变暖的威胁，这导致了为石油衍生燃料和商品化学品提供替代和可再生路线的挑战。然而，任何这样的方法在被认为具有工业相关性之前都面临着在产率和成本方面的严格要求。此外，油衍生化合物（即烃）的生产或其功能化不属于可以被认为是“标准”生物化学库的范围。因此，据报道，极少数生物催化剂、途径或生物体可能支持这种过程。因此，虽然挑战已经明确，但找到合适的解决方案的途径还远未明确，并且对于可以生产商品化学品如丁二烯（合成橡胶的前体）和芳香族二羧酸（PET和其他聚合物的前体）的新生物催化剂存在未满足的工业需求。我们最近已经能够提供一些详细的见解的机制的UbiD家族的酶。这些作为可逆的脱羧物（即添加或去除CO2基团到/从有机分子）。我们和其他人已经表明，它们能够将不饱和烃（即含有双键）与相应的羧酸（即含有额外的CO2基团的形式）相互转化。已经报道了各种各样的底物，并且催化的反应似乎容易可逆，这取决于[CO2]水平。我们最近对这些酶的研究已经建立了通过利用以前未知的酶辅因子来实现这种不寻常的化学反应。在本项目中，我们试图完成我们对这种辅因子是如何产生的，以及它是如何失活的理解，以指导未来的应用。在我们的基本理解的基础上，我们试图推导出新的和绿色生产路线，以商品化学品使用可再生原料作为UbiD底物。更具体地说，在这项资助中，我们将寻求确定UbiD酶可以进化到什么程度来生产丁二烯和芳香族二羧酸等化合物。我们将分别使用可再生原料粘康酸和苯甲酸作为UbiD底物。我们的研究结果将提供概念证明，并概述了未来生物技术应用的范围。

The projected depletion of fossil oil resources, and the threat of global warming as a direct consequence of their continued use, has led to the challenge of providing alternative and renewable routes to oil derived fuels and commodity chemicals. However, any such process faces severe demands in terms of yield and costs before it can be considered industrially relevant. In addition, the production of oil derived compounds (ie hydrocarbons) or their functionalization does not belong to what can be considered the "standard" biochemical repertoire. Hence, comparably few biocatalysts, pathways or organisms have been reported to might support such processes. Therefore, while the challenge is clearly defined, the route to a suitable solution if far from clear, and there is an unmet industrial need for new biocatalysts that can produce commodity chemicals such as butadiene (precursor to synthetic rubber) and aromatic dicarboxylic acids (precursors to PET and other polymers). We have recently been able to provide some detailed insights into the mechanism of the UbiD family of enzymes. These act as reversible decarboxylates (ie adding or removing a CO2 group to/from an organic molecule). We and others have shown they are able to interconvert unsaturated hydrocarbons (ie containing a double bond) with the corresponding carboxylic acids (ie version containing the additional CO2 group). A wide range of substrates has been reported, and the reaction catalysed appears readily reversible depending on [CO2] levels. Our recent work on these enzyme has established the achieve this unusual chemistry by making use of a previously unknown enzyme cofactor. In this project, we seek to complete our understanding of how this cofactor is made, and also how it is inactivated, to guide future application.Building on our fundamental understanding, we seek to derive novel and green production routes to commodity chemicals using renewable feedstocks as UbiD substrates. More specifically, in this grant we will seek to establish to what extend UbiD enzyme can be evolved to produce compounds such as butadiene and aromatic dicarboxylic acids. We will make use of the renewable feedstocks muconic and benzoic acid as UbiD substrates respectively. Our results will provide proof of concept and outline the scope for future biotechnological application.