Fermentation of xylose with the yeast Pachysolen tannophilus

Abstract

Pachysolen tannophilus IfGB 0101, is able to grow aerobically on xylose, glucose and fructose. Galactose too is assimilated after long adaption times. In the complete absence of oxygen, xylose is fermented, forming mainly xylitol, lower amounts of ethanol and CO2. According to the mass balance, it may be concluded that the pentose phosphate enzymes together with the oxidative phosphogluconate way are in action simultaneously. At semi-aerobic conditions (0.45 l air per liter, per hour) ethanol production is somewhat increased but no aeration conditions could as yet be found at which ethanol was the main fermentation product. The significance of xylitol formation seems to be mainly that of an electron sink of the phosphogluconate pathway.