Fast determination of biocatalyst process stability

A major bottleneck in developing industrial enzymes is the lack of a method for determining catalyst process stability quickly and efficiently. In ord er to solve this problem, a new method for the fast in-situ characterisatio n of activity and long-term stability has been developed. The necessary the ory of modelling enzyme activation and deactivation is presented. As a mode l reaction we have chosen the carboxy-esterhydrolase-catalyzed hydrolysis o f triglycerides. These reactions were performed in a fed-batch and continuo us flow reactor. To accelerate the process of ageing, the temperature was c ontinuously increased during the experiments. The procedure of parameter de termination on the basis of experimental results is described for first-ord er, series and parallel deactivation mechanisms. Additionally, several crit eria for choosing the applicable mechanism are presented. As an application of the new method, the influence of immobilisation on activity and stabili ty of the immobilised enzymes was investigated. The temperature dependency of characteristics such as initial activity, half-life time and turn-over-n umber were determined. (C) 1998 Elsevier Science Ltd. All rights reserved.