Protocols have been developed for the synthesis of some biocatalysts:
a) trypsin conjugated with Eudragit S 100, Eupergit C and silica;
b) aminopeptidase conjugated with Eupergit C;
c) penicillin acylase G conjugate with poly(N-isopropylacrylamide).
Results from some of these new biocatalysts are very positive, e.g. trypsin and aminopeptidase with Eupergit C, which gave good results both in terms of stability and possibility of reuse (but some improvement are necessary mainly on recovery of enzymatic activity).
In other cases, research gave interesting results, but some modification to improve general properties are required. For instance, despite the fact that the concept of using soluble enzyme-formulations is very attractive, smart polymers bound to penicillin acylase require significant improvement in order to be of use in the enzymatic coupling process to semi-synthetic antibiotics. A new compound prepared by the University of Lund, solubility properties of which can be finely tuned on both temperature and pH directly in the synthesis phase could overcome most problems risen until now.
Other directions of the research to solve some of the problems faced until now are now clearer; research must be focused on:
a) loading of the enzyme thereby increasing the activity per gram of enzyme-preparation;
b) swelling properties: minimising the volume of the enzyme-preparation;
c) recovery of the insoluble enzyme from an aqueous solution.
Finally, interactions among enzymes and polyelectrolytes have been characterised, and soon this knowledge will be applied to improve biocatalysts properties.
Objectives and content
The project has the objectives: to produce novel biocatalyst materials based on biological molecules, with enhanced properties, to be used in bio-transformation processes; to adapt technologies for their production to larger scale requirements of industrial biotransformation processes; to demonstrate the enhanced stability and functionality of new biocatalysts in chosen biotransformation processes. The project handles the priority research tasks of the sub-area 2.1 Materials Engineering: 2.1.3.S "Integration of traditional materials with new materials systems..." and 2.1.4.M "New functionalised materials for various applications", possibly contributing to task 2.1.2.S "Processing technologies to make advanced materials, and chemical intermediate compounds..." and task 2.1 .3.M "Environmentally compatible surface engineering...". The most important innovative point is in the fact that the project aims at promoting the incorporation of a new technology resulting from the combination of the two innovations developed previously and of traditional immobilisation techniques into such traditional sector as pharmaceutical and fine chemicals industries. This multidisciplinary technology might prove to be of potential interest for widespread application wherever enzyme-catalysed biotransformation are either already employed or can be used to improve process performance. The latter point adds additional value to the presentproposal. The technical basis of the present project consists in two main points. The first one is based on the application of a novel method of thin bio-organic film deposition (Partner 1) which enables easy inclusion of protein layers in the desired position of the layered structure to be deposited without any contact of proteins with air medium, thus preventing protein denaturation, protecting protein layers by mono-layer coatings afterwards and increasing stability. In addition, this method might permit to reduce consumption of expensive biological materials by increasing specific volumetric activity. The second technical approach consists in the combination of the developed methods of stabilisation of protein functional properties (Partner 2) with the above technique of film deposition by introducing polymeric compounds into biocatalysts.
The combination of both above approaches with traditional and purpose-modified immobilisation techniques creates the basis for creation of feasible biotransformation processes at plant scale. The combination of the above methods might enable control of substrate/product transport and of reaction equilibria. The industrial aims lie also in the possibility, by utilising the biocatalysts designed within the project, to eliminate recycles, organic waste and achieve more adequate downstream processing including more efficient separation of end products. The overall improvement of biocatalyst performance is expected to reach at least 25-50 %, constituted by contributions to stability, process condition improvements. The industrial objectives of the project will be warranted by two the participation of four industrial companies: two SMEs providing and developing the core technologies, an SME utilising enzyme-catalysed synthesis processes, and a larger industrial pharmaceuticals company (backed by two large companies operating in pharmaceutical and fine chemical fields) that would supply the biological materials and exploit the results of the project The goals are in complete accordance with business strategies of these companies.BE97-5141
Funding SchemeCSC - Cost-sharing contracts
LS2 3AR Leeds
6167 RA Geleen
221 00 Lund