Modeling simultaneous glucose and xylose uptake in Saccharomyces cerevisiae from kinetics and gene expression of sugar transporters.
A kinetic model for glucose and xylose co-substrate uptake in Saccharomyces cerevisiae is presented. The model couples the enzyme kinetics with the glucose-dependent genetic expression of the individual transport proteins. This novel approach implies several options for optimizing the co-substrate utilization. Interestingly, the simulations predict a maximum xylose uptake rate at a glucose concentration >0 g/L, which suggests that the genetic expressions of the considered transport proteins are of importance when optimizing the xylose uptake. This was also evident in fed-batch simulations, where a distinct optimal glucose addition rate >0 g/L x h was found. Strategies for improving the co-substrate utilization by genetic engineering of the transport systems are furthermore suggested based on simulations.
Bertilsson
Magnus
M
Department of Chemical Engineering, Lund University, Box 124, 221 00, Lund, Sweden. magnus.bertilsson@chemeng.lth.se
Andersson
Jonas
J
Lidén
Gunnar
G
D003198:Computer Simulation; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism*
D009004:Monosaccharide Transport Proteins; D014994:Xylose; D005947:Glucose