Chauhan, Rashmi Pradeepsingh; (1997) In-situ product removal from enzyme catalysed biotransformations. Doctoral thesis (Ph.D), UCL (University College London).

Text In-situ_product_removal_from_e.pdf Download (16MB)

Abstract

The application of in-situ product removal (ISPR) (the concurrent recovery of a product during the product formation process) has been investigated as a means of improving the productivity of biotransformations. An Escherichia coli transketolase (TK) catalysed reaction was chosen as a representative system, where glycolaldehyde and β-hydroxypyruvate were converted to L-erythrulose and carbon dioxide. The principal components of the reaction were small, hydrophilic, polar and non-volatile molecules. Ion exchange methods, heterocomplex formation, carbonaceous adsorbents and separations based on phenylboronate-diol interactions were investigated as potential ISPR techniques for the recovery of L-erythrulose. Each method was assessed on the basis of its capacity, selectivity, interference and reversibility characteristics within the reaction medium. Afifi-Gel® 601 and Ambersorb® 572 were chosen to perform ISPR from the test biotransformation in combination with a number of operational strategies to help overcome low selectivities exhibited by these carriers. Although there was little or no indication for the use of either ISPR method to increase productivities within the representative system, with other more complex TK catalysed reactions, the benefits of ISPR should become more apparent. Hence, from studying this type of reaction, we have devised a systematic approach for selection and testing of an ISPR method. The necessary steps are to characterise the process and its components, to assess any selectivity or interference problems of the potential ISPR technique, and to appraise the benefits of the selected ISPR method.

Download activity - last month

Export as XMLJSONCSV

Download activity - last 12 months

Export as CSVXMLJSON

Downloads by country - last 12 months

Export as CSVJSONXML

Archive Staff Only

View Item