Microtools for downstream processing

生物催化使用酶来实现更绿色的生产过程。为了充分利用这项技术的优势，不仅需要了解反应步骤，即生产所需产品的步骤，而且要了解将所需产品从副产品和残留(即未反应)底物中分离出来的步骤。这通常需要几个提纯步骤。通常正是这些提纯步骤的成本决定了这种生物催化过程的经济可行性。为了快速了解这些提纯步骤的工艺和操作条件--进而决定整个工艺的成本和可行性--有必要快速分析不同的提纯步骤，并选择最有效的一个(S)。这样的调查进行得越快，关于经济可行性的关键决定就能越快做出，产品就能越快地推向市场。在这里，我们建议利用微制造技术的进步来创造能够模仿通常用于提纯的较大设备的微型设备，以便可以更快地评估不同的步骤。小型化将意味着更经济有效地利用资源进行调查。微型化还意味着可以更详细地研究特定的效应。例如，我们设想研究产品分子如何从一种溶剂(例如水溶液)‘过渡’到另一种溶剂(例如有机溶剂)的效果，以及在什么条件下它们在所谓的液-液萃取过程中表现最好。然后我们将使用这些信息来确定应该如何设计更大的系统(即产品将有效地生产和提纯的系统)来提高产量。这种产量的提高应该会使生物催化成为一种更环保的过程，并使其在经济上更可行。

Biocatalysis uses enzymes to enable greener production process. To fully harness the advantages of this technology, it isnecessary to understand not only the reaction steps, i.e. the steps where the desired product is produced, but also thosesteps where the desired product is separated from by-products and residual (i.e. unreacted) substrate. This typicallyrequires several purification steps. And it is often the cost of these purification steps which determine the economic viabilityof such a biocatalytic process. To rapidly understand the process and operating conditions of these purification steps -which in turn determines the cost and viability of the whole process - it is necessary to rapidly analyse different purificationstep 'candidates' and select the most efficient one(s). The more rapidly such an investigation can be conducted, the fastercritical decisions about the economic viability can be taken, and the faster one can bring a product to the market.Here, we propose to use the advances in microfabrication to create miniaturised devices which can mimic the larger onestypically used for purification, so that the different steps can be evaluated more rapidly. Miniaturisation will mean a morecost-effective use of resources to undertake the investigations. Miniaturisation will also mean that particular effects can bestudied with greater detail. We envisage for example to study the effects of how product molecules 'transition' from onesolvent (e.g. aqueous one) to another solvent (e.g. an organic one), and under what conditions they do so best, in aprocess that is called liquid-liquid extraction. We will then use this information to determine how larger systems (ie thesystems where the products will effectively be produced and purified) should be designed to improve their yield. Such animprovement in yield should make biocatalysis an even greener process and make it also economically more viable.