Comparison of the xylose reductase-xylitol dehydrogenase and the xylose isomerase pathways for xylose fermentation by recombinant Saccharomyces cerevisiae

Table 4 Comparison of XI and XR-XDH-carrying laboratory strains and the industrial XR-XDH carrying strain TMB 3400.

		Anaerobic fermentation		Enzyme activity U/mg protein								Reference
Strain	Aerobic growth rate xylose h^-1	Xylose cons. rate g xylose g cells^-1 h^-1	Ethanol yield g ethanol g consumed sugar^-1	XI	XR	XDH	XK	TAL	TKL	RKI	RPE
TMB 3057	0.16	0.13	0.33	-	0.35	2.16	0.89*	0.91*	0.06*	0.14*	0.09*	[29]
TMB 3066	0.02	0.05	0.43	0.82	-	-	0.89*	0.91*	0.06*	0.14*	0.09*	This work
RWB217	0.22	0.50 **	0.43	0.3–1.1	-	-	+	+	+	+	+	[28]
TMB 3400	0.14	0.06	0.34	-	0.09	0.59	+	↑	↑	n.a.	n.a.	[55]

Aerobic growth rates on xylose, average xylose consumption rate for 50 hours of fermentation, and ethanol yield for anaerobic xylose fermentation are presented together with the enzyme activities of relevant enzymes are presented. (+ overexpressed by genetic engineering; ↑ upregulated upon mutagenesis).
* Measured for strain background TMB 3044
** Average rate for batch fermentation recalculated from [28] to allow comparison

ISSN: 1475-2859