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Table 2 XR, XDH, XK activities, ethanol and xylitol productivity of H. polymorpha transformants and control strain

From: Engineering of xylose reductase and overexpression of xylitol dehydrogenase and xylulokinase improves xylose alcoholic fermentation in the thermotolerant yeast Hansenula polymorpha

Strain Activity [U (mg protein-1)] Productivity [mg (L h)-1]/[mg (L g h)-1]
  XR XDH XK   
  NADPH/KM (μM) NADH/KM (μM)    Ethanol Xylitol
XRn 0.091 ± 0.005/9 ± 0.5 0.016 ± 0.001/100 ± 5.5 0.551 ± 0.035 - 6.3 ± 0.3/2.75 ± 0,11 3.6 ± 0.2/1.56 ± 0.1
XRm 0.01 ± 0.001/152 ± 8.4 0.014 ± 0.001/112 ± 6.5 0.504 ± 0.028 - 9.8 ± 0.4/4.45 ± 0.19 3.2 ± 0.2/1.45 ± 0.07
XRn/XDH - - 1.3 ± 0.07 - 12 ± 0.5/5.7 ± 0.3 3.1 ± 0.2/1.48 ± 0.07
XRm/XDH - - 1.485 ± 0.087 - 18.4 ± 0.9/8.76 ± 0.35 1.6 ± 0.1/0.76 ± 0.04
XRn/XDH/XK - - - 0.375 ± 0.021 13.8 ± 0.6/6.4 ± 0.3 2.8 ± 0.1/1.3 ± 0.06
XRm/XDH/XK - - - 0.366 ± 0.019 54.7 ± 2.7/21.9 ± 1.1 0.9 ± 0.04/0.36 ± 0.02
CBS4732 0.034 ± 0.025/7 ± 0.4 0.012 ± 0.001/85 ± 4.7 0.697 ± 0.049 0.156 ± 0.009 7.5 ± 0.4/3.3 ± 0.2 4.2 ± 0.2/1.8 ± 0.09
  1. XRn – transformant bearing normal XYL1 gene; XRm – transformant bearing modified XYL1 gene (XYL1m).
  2. - not determined