Identification of white-rot and soft-rot fungi increasing ethanol production from spent sulfite liquor in co-culture withSaccharomyces cerevisiae

Abstract

To identify fungi that are capable of increasing ethanol production from lignocellulose in spent sulfite liquor. In a batch fermentation study, the fungal mix could produce 24.61 g l(-1) ethanol using spent sulfite liquor as substrate. The fungal mix grew well on glucose, xylose, hemicellulose and cellulose. In addition, we were able to identify the fungal mix by use of PCR-amplification of DNA and sequencing, and they were identified as Chalara parvispora and Trametes hirsuta/T. versicolor. In a reconstitution study, the identified fungi were shown to produce equal amount of ethanol as the fungal mix. We were also able to show that C. parvispora could produce ethanol from xylose. The present study has shown that ethanol production from biomass can be increased by use of C. parvispora and T. versicolor when compared with fermentation using only S. cerevisiae. The study shows that refining biomass by ethanol production from spent sulfite liquor, a lignocellulose material, can be increased by adding C. parvispora and T. versicolor, and it is thus of great potential economical impact.