Temperature mediated changes of d-xylose metabolism in the yeastPachysolen tannophilus

Abstract

We found that during d-xylose fermentation to ethanol by Pachysolen tannophilus the amount of xylitol produced decreased dramatically while CO2 increased when the temperature was raised from 30 to 37°C. Acetaldehyde was detected only at 37°C. However, no significant change in the amount of ethanol production was observed. A similar trend was observed when the cells were treated with 10 μM 2,4-dinitrophenol. Furthermore, the enzyme d-xylose reductase displayed a similar activation energy in cells grown either at 30 or 37°C. These data suggest that in P. tannophilus oxidative phosphorylation becomes uncoupled at higher temperature.