Process optimisation and scale-up of industrial enzymes production

Anane, Emmanuel (2013-12)

Thesis (MScEng)--Stellenbosch University, 2013.

Thesis

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.

AFRIKAANSE OPSOMMING: Industriële ensieme bied uitstekende vooruitsigte vir die ontwikkeling van ‘groen’ prosesse en hoë-waarde produkte wat gelyktydig ʼn verminderde negatiewe impak op die omgewing het. Die doel van hierdie studie was om semi-enkellading kultuur metodologieë te ontwikkel om die produksie van twee industrieel-relevante ensieme in twee toegewyde gisproduksiesisteme, naamlik Saccharomyces cerevisiae en Pichia pastoris, op laboratorium- en lootsaanlegskaal te verbeter. Hierdie doel is bereik deur spesifiek op sleutel bioprosesparameters, naamlik die substraat voersnelheid tydens semi-enkellading kultuur, fermentasie prosestoestande, ondermeer die opgeloste suurstofspanning (OSS), groeimediumverbetering en opskaleringseffekte tydens ensiemproduksie, te fokus. In die eerste gissisteem is die glukose voersnelheid gebruik om die spesifieke groeisnelheid van S. cerevisiae vir die produksie van α-glukuronidase te optimeer. ʼn Semi-gedefinieerde groeimedium is vir die tweede gissisteem ontwikkel en beide die substraat voersnelheid en die OSS is vir die produksie van β-fruktofuranosidase (FFase) deur Pichia pastoris geoptimeer. Deur hierdie twee gissisteme te gebruik kon die potensiaal vir optimering van semi-enkellading kulture vir die maksimering van industriële ensiemproduksie deur geneties-gemanipuleerde giste op hoogs doeltreffende wyse gedemonstreer word.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/95463
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