Fermentation of Xylose and Xylans by Kluyveromyces Marxianus IMB Strains

Abstract

The screening of the IMB strains showed that IMB2 performed the best at 40 degrees Celsius on xylose fermentation with an ethanol yield of 0.07g/g and a xylitol yield of 0.42g/g. IMB2 showed in the SSF experiment the best ethanol production at 40 degrees Celsius with 18.6% of the theoretical maximum yield with no significant difference in enzyme concentration. Xylitol production was best at 40�C with 15.8% of the theoretical maximum yield and 2l/ml enzyme concentration. The monoculture of IMB2 showed poor results in ethanol production at the co-culture conditions. The co-culture showed better results in ethanol production which was derived by P. stipitis. P. stipitis as monoculture had the highest conversion efficiency with 84%. An interesting finding was the high xylitol production by IMB2 as monoculture. The conversion efficiency was 65% and is comparable to other in the literature mentioned yeast strains. It can be concluded that the K. marxianus IMB strains are not suitable for ethanol production at thermophilic conditions with xylose as sole carbon source. K. marxianus was found as a potential strains for xylitol production.