Process optimisation and scale-up of industrial enzymes production

[摘要] ENGLISH ABSTRACT: Industrial enzymes offer excellent prospects for the development of 'green' processes and high quality products with a diminished negative impact on the environment. This study endeavours to develop fed-batch process methods to improve the production of two industrially relevant enzymes in dedicated yeast systems, namely Saccharomyces cerevisiae and Pichia pastoris, at laboratory and pilot scale. This goal was achieved by specifically focussing on key bioprocessing parameters, namely the substrate feed rate during fed-batch fermentation, fermentation process conditions including the dissolved oxygen tension (DOT), growth medium improvement and scale-up effects during enzyme production. In the first system, the glucose feed rate was used to optimise the specific growth rate of recombinant Saccharomyces cerevisiae for the production of α-glucuronidase. In the second system, a semi-defined growth medium was developed, and both the substrate feed rate and DOT were optimised in the production of β-fructofuranosidase (FFase) by Pichia pastoris. These two systems serve to demonstrate the potential for optimisation of fed-batch cultures to maximise production of industrial enzymes by engineered yeasts.

[发布机构] Stellenbosch University