TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: The microorganism is recombinant or non-recombinant microorganism. The contact is performed in a large-scale fermentation vessel. The vessel is adapted to provide suitable conditions for fermentation of one or more carbohydrate into fermentation end-products. The microorganism is capable of direct fermentation of 5C and 6C carbohydrates. The microorganism is bacterium, preferably species of Clostridia, more preferably Clostridium phytofermentans. The recombinant microorganism comprises one or more heterologous polynucleotides or one or more copies of an endogenous polynucleotide that enhance the activity of one or more cellulases. The biomass comprises one or more of corn steep solids, corn steep liquor, malt syrup, xylan, cellulose, hemicellulose, fructose, glucose, mannose, rhamnose, xylose, municipal waste, wood, plant material, plant material extract, natural or synthetic polymer, switchgrass, bagasse, corn stover, poplar biomass or their combinations. The biomass comprises a higher concentration of oligomeric carbohydrates relative to monomeric carbohydrates. The heterologous polynucleotide or copy of endogenous polynucleotide has a defined C.phytofermentans derived sequence of 4904, 1563, 3267, 3421, 2636 or 1688 base pairs (SEQ ID No. 1, 2, 5, 8, 11 or 14), given in the specification. The one or more heterologous polynucleotides or the one or more copies of an endogenous polynucleotide encode one or more enzymes chosen from Cphy3202, Cphy2058, Cphy1163, Cphy3367, Cphy1100, Cphy1510, Cphy3368 and Cphy2128. The cellulase is in an amount of 0.4-15 filter paper unit (FPU)/g cellulose. The enhanced activity is equivalent to addition of the cellulases in an amount sufficient to provide activity of 0.4-15 FPU/g cellulose. The hydrolysis results in a greater concentration of cellobiose and/or larger oligomers, relative to monomeric carbohydrates. The biomass is pre-conditioned with alkali treatment. The recombinant microorganism produces one or more hydrolytic enzyme encoded by a variant having a polynucleotide sequence with an identity of 70% or more compared to a sequence chosen from SEQ ID No. 1, 2, 5, 8, 11 and 14. EXAMPLE - Fermentation of corn stover biomass was carried out as follows. Corn stover was pretreated with sodium hydroxide. The pretreated stover was blended with yeast extract (in g/l) (10), corn steep powder (5), dipotassium hydrogen phosphate (3), potassium dihydrogen phosphate (1.6), trisodium citrate (2), citric acid (1.2), ammonium sulfate (0.5), sodium chloride (1), cysteine hydrochloride (1) and deionized water. The mixture was fermented in a single fermentation vessel containing inoculum of Clostridium phytofermentans (2x 109 cells/ml) and endocellulase (3.36 filter paper unit/g glucan). The culture was carried out at pH 6.5 and 35 degrees C for 120 hours. After culture, the saccharification yield and ethanol yield were measured. Results showed that ethanol was produced at yield of 95%, and the saccharification yield was 116%.