Comparative metabolic network analysis of two xylose fermenting recombinant Saccharomyces cerevisiae strains

Grotkjaer, T; Christakopoulos, P; Nielsen, J; Olsson, L

dc.contributor.author	Grotkjaer, T	en
dc.contributor.author	Christakopoulos, P	en
dc.contributor.author	Nielsen, J	en
dc.contributor.author	Olsson, L	en
dc.date.accessioned	2014-03-01T01:22:00Z
dc.date.available	2014-03-01T01:22:00Z
dc.date.issued	2005	en
dc.identifier.issn	10967176	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16431
dc.subject	Carbon labelling	en
dc.subject	Ethanol	en
dc.subject	Glucose	en
dc.subject	Metabolic engineering	en
dc.subject	Metabolic network analysis	en
dc.subject	NADH	en
dc.subject	NADPH	en
dc.subject	Saccharomyces cerevisiae	en
dc.subject	Xylose	en
dc.subject	Yeast	en
dc.subject.other	Ethanol	en
dc.subject.other	Glucose	en
dc.subject.other	Metabolism	en
dc.subject.other	Redox reactions	en
dc.subject.other	Xylose	en
dc.subject.other	Carbon labelling	en
dc.subject.other	Metabolic engineering	en
dc.subject.other	Redox metabolism	en
dc.subject.other	Saccharomyces cerevisiae	en
dc.subject.other	Yeast	en
dc.subject.other	alcohol	en
dc.subject.other	ammonia	en
dc.subject.other	carbon 13	en
dc.subject.other	glucose	en
dc.subject.other	glutamate dehydrogenase	en
dc.subject.other	glyoxylic acid	en
dc.subject.other	oxidoreductase	en
dc.subject.other	reduced nicotinamide adenine dinucleotide	en
dc.subject.other	reduced nicotinamide adenine dinucleotide phosphate	en
dc.subject.other	xylose	en
dc.subject.other	anaerobic metabolism	en
dc.subject.other	analysis	en
dc.subject.other	article	en
dc.subject.other	carbohydrate metabolism	en
dc.subject.other	controlled study	en
dc.subject.other	enzyme activity	en
dc.subject.other	fermentation	en
dc.subject.other	fungal metabolism	en
dc.subject.other	fungal strain	en
dc.subject.other	fungus culture	en
dc.subject.other	fungus growth	en
dc.subject.other	gene deletion	en
dc.subject.other	gene overexpression	en
dc.subject.other	genetic recombination	en
dc.subject.other	isotope labeling	en
dc.subject.other	nonhuman	en
dc.subject.other	oxidation reduction reaction	en
dc.subject.other	priority journal	en
dc.subject.other	Saccharomyces cerevisiae	en
dc.subject.other	Computer Simulation	en
dc.subject.other	Energy Metabolism	en
dc.subject.other	Gene Expression Regulation, Fungal	en
dc.subject.other	Genetic Enhancement	en
dc.subject.other	Models, Biological	en
dc.subject.other	Multienzyme Complexes	en
dc.subject.other	Recombination, Genetic	en
dc.subject.other	Saccharomyces cerevisiae	en
dc.subject.other	Saccharomyces cerevisiae Proteins	en
dc.subject.other	Signal Transduction	en
dc.subject.other	Species Specificity	en
dc.subject.other	Xylose	en
dc.subject.other	Fungi	en
dc.subject.other	Saccharomyces cerevisiae	en
dc.title	Comparative metabolic network analysis of two xylose fermenting recombinant Saccharomyces cerevisiae strains	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.ymben.2005.07.003	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.ymben.2005.07.003	en
heal.publicationDate	2005	en
heal.abstract	The recombinant xylose fermenting strain Saccharomyces cerevisiae TMB3001 can grow on xylose, but the xylose utilisation rate is low. One important reason for the inefficient fermentation of xylose to ethanol is believed to be the imbalance of redox co-factors. In the present study, a metabolic flux model was constructed for two recombinant S. cerevisiae strains: TMB3001 and CPB.CR4 which in addition to xylose metabolism have a modulated redox metabolism, i.e. ammonia assimilation was shifted from being NADPH to NADH dependent by deletion of gdh1 and over-expression of GDH2. The intracellular fluxes were estimated for both strains in anaerobic continuous cultivations when the growth limiting feed consisted of glucose (2.5 g L-1) and xylose (13 g L-1). The metabolic network analysis with13C labelled glucose showed that there was a shift in the specific xylose reductase activity towards use of NADH as co-factor rather than NADPH. This shift is beneficial for solving the redox imbalance and it can therefore partly explain the 25% increase in the ethanol yield observed for CPB.CR4. Furthermore, the analysis indicated that the glyoxylate cycle was activated in CPB.CR4. © 2005 Elsevier Inc. All rights reserved.	en
heal.journalName	Metabolic Engineering	en
dc.identifier.doi	10.1016/j.ymben.2005.07.003	en
dc.identifier.volume	7	en
dc.identifier.issue	5-6	en
dc.identifier.spage	437	en
dc.identifier.epage	444	en