反应详情

Strains Y-PsNative, Y-PsK270M and Y-PsK270R (cf example 4) were compared in anaerobic batch fermentation with 20 g l−1 glucose and 50 g l−1 xylose (FIG. 3). Table 6 summarizes xylose consumption, ethanol concentration and product yields after 117 hours of fermentation. The reference strain Y-PsNative consumed 30.4 g l−1 xylose and produced 16.7 g l−1 ethanol while Y-PsK270R consumed 46.1 g l−1 xylose and produced 25.3 g l−1 ethanol. Y-PsK270M consumed the least xylose (16.8 g l−1) and produced the lowest ethanol concentration (14.1 g l−1) of the three strains. The reference strain Y-PsNative produced an ethanol yield of 0.33 g ethanol g consumed sugars−1 and a xylitol yield of 0.26 g xylitol g consumed xylose−1. Both strains with mutated XR produced higher ethanol yields (0.38 g ethanol (g consumed sugars)−1) and significantly lower xylitol yields (0.09 g xylitol (g consumed xylose)−1) than the reference strain. In addition, Y-PsK270R grew and produced biomass anaerobically from xylose after glucose depletion (FIG. 4). Y-PsK270R had produced 3.4 g l−1 biomass after 117 hours of fermentation while both Y-PsNative and Y-PsK270M produced 2.1 g l−1 biomass.

1. customxylose consumption, ethanol concentration and product
2. customyields after 117 hours of fermentation
3. customThe reference strain Y-PsNative consumed 30.4 g l−1 xylose
4. customproduced 16.7 g l−1 ethanol
5. customwhile Y-PsK270R consumed 46.1 g l−1 xylose
6. customproduced 25.3 g l−1 ethanol
7. customY-PsK270M consumed the least xylose (16.8 g l−1)
8. customproduced
9. concentrationthe lowest ethanol concentration (14.1 g l−1) of the three strains
10. customThe reference strain Y-PsNative produced an ethanol yield of 0.33 g ethanol
11. customg consumed sugars−1
12. customa xylitol yield of 0.26 g xylitol g consumed xylose−1
13. customBoth strains with mutated XR produced higher ethanol