Microtools for downstream processing

Biocatalysis uses enzymes to enable greener production process. To fully harness the advantages of this technology, it is
necessary to understand not only the reaction steps, i.e. the steps where the desired product is produced, but also those
steps where the desired product is separated from by-products and residual (i.e. unreacted) substrate. This typically
requires several purification steps. And it is often the cost of these purification steps which determine the economic viability
of 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 purification
step 'candidates' and select the most efficient one(s). The more rapidly such an investigation can be conducted, the faster
critical 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 ones
typically used for purification, so that the different steps can be evaluated more rapidly. Miniaturisation will mean a more
cost-effective use of resources to undertake the investigations. Miniaturisation will also mean that particular effects can be
studied with greater detail. We envisage for example to study the effects of how product molecules 'transition' from one
solvent (e.g. aqueous one) to another solvent (e.g. an organic one), and under what conditions they do so best, in a
process that is called liquid-liquid extraction. We will then use this information to determine how larger systems (ie the
systems where the products will effectively be produced and purified) should be designed to improve their yield. Such an
improvement in yield should make biocatalysis an even greener process and make it also economically more viable.

Biocatalysis can replace traditional chemical catalysis based procesess resulting in a greener production process. However, the reaction step of such a biocatalysis process needs to be integrated with one or several purification steps to recover products and/or remove inhibitory substances. The economical feasibility of a bio-based process is typically dependent to a large extent on the efficiency and the cost of the subsequent separation steps. Consequently, a series of separation process candidates have to be investigated with the purpose of achieving the most efficient downstream processing configuration. The more rapidly such an investigation can be conducted, the faster critical decisions about economical feasibility of a bio-based process can be taken, and the faster one can bring a product on the market. The main objective of this project is to establish a microscale downstream processing toolbox which can be used for rapid and high content screening or for process development. The following main results are expected to be obtained:
1) New and existing building blocks of a miniaturised downstream processing toolbox will be developed, standardized and evaluated. The toolbox will include separation processes based on extraction, pervaporation, adsorption, absorption and membrane technology.
2) The toolbox will be supplemented by advanced on-line measurements and rational experimentation protocols for rapid and accurate generation of data for downstream process characterization and development.
3) Scaling-up of the results obtained with the miniaturised downstream processing toolbox will be evaluated on the basis of lab-scale and pilot-scale experiments.
4) Separation process sequences will be developed for two challenging and industrially relevant case studies (transketolase, transaminase) in order to demonstrate the practical applicability of the miniaturised downstream process development toolbox.

Production of chiral amines is important in the fine chemical industry, specifically for pharmaceutical applications.Transaminase-based processes, for example, are attractive for the pharmaceutical industry due to their capability of producing optically pure products. Time is money in the pharmaceutical industry, and any technological development that leads to shorter process development time - as is the case with the proposed miniaturised downstream processing toolbox - potentially has a major impact on the competitiveness of the traditional research-based pharmaceutical industry due to the
limited patent life time. Moreover, the fact that the microfluidic separation devices in the toolbox are all envisaged to be compatible with continuous process operation also fits nicely in the current trend in the pharmaceutical industry to replace relatively large batch reactors by continuous processes at micro-scale or meso-scale. Moving from batch towards continuous pharmaceutical manufacturing is one of the key strategies in the pharmaceutical industry for improving safety and product quality while decreasing waste generation and manufacturing costs. Development of continuous separation
methods at micro-scale is considered to be one of the current bottlenecks for the future development of such continuous micro-scale reaction sequences. Also here, the project results are expected to make a major impact. For process development, novel analytical methods are required. The proposed development of a bespoke UV absorbance based, dual-wavelength detection system (subcontracting to Paraytec) for the rapid detection and determination of product and substrate concentrations will provide valuable insight on how to optimise operation of liquid-liquid extraction systems. It will also directly offer assistance to an SME company in the UK who will receive funds to develop a new piece of equipment, and via the proposed research and the several collaborators in Europe, receive direct input on the performance of the device.