Various techniques are available for the conversion of lignocellulosics to fuel ethanol.
During the last decade processes based on enzymatic hydrolysis of cellulose have been
investigated more extensively, showing good yield on both hardwood and softwood. The
cellulase production of a filamentous fungi, Trichoderma reesei Rut C 30, was examined
on carbon sources obtained after steam pretreatment of spruce.
These materials were washed fibrous steam-pretreated spruce (SPS), and hemicellulose
hydrolysate. The hemicellulose hydrolysate contained, besides water-soluble carbohydrates,
lignin and sugar degradation products, which were formed during the pretreatment and
proved to be inhibitory to microorganisms. Experiments were performed in a 4-L laboratory
fermentor. The hydrolytic capacity of the produced enzyme solutions was compared with
two commercially available enzyme
preparations, Celluclast and Iogen Cellulase, on SPS, washed SPS, and Solka Flee cellulose
powder. There was no significant difference among the different enzymes produced by
T, reesei Rut C 30. However, the conversion of cellulose using these enzymes was higher
than that obtained with Iogen or Celluclast cellulases using steam-pretreated spruce