Table 2.

Specific activities of xylose isomerase and xylulokinase in R. jostii RHA1, R. opacus PD630, and their recombinants^a

Strain (carbon source)	Sp act (U/mg protein)
	Xylose isomerase	Xylulokinase
R. jostii RHA1 (glucose)	NDb	0.16 ± 0.02
R. jostii XYLA (glucose)	0.27 ± 0.01	0.17 ± 0.04
R. jostii XYLA (xylose)	0.39 ± 0.02	0.53 ± 0.10
R. jostii XYLAB (xylose)	0.40 ± 0.05	4.89 ± 0.61
R. opacus PD630 (glucose)	ND	0.21 ± 0.01
R. opacus XYLA (glucose)	0.20 ± 0.01	0.23 ± 0.02
R. opacus XYLA (xylose)	0.42 ± 0.05	0.46 ± 0.03
R. opacus XYLAB (xylose)	0.37 ± 0.02	2.96 ± 0.30

^aThe data were calculated from triplicate measurements, and data are represented as the average ± standard deviation. Glucose or xylose at 20 g/liter was used as the carbon source in this study.

^bND, not detected.