TECHNOLOGY FOCUS - BIOLOGY - Preparation: No preparation method is given. Preferred Components: In the polypeptide, at least one amino acid of the amino acid sequence is altered compared to the amino acid sequence having SEQ ID NO: 2, where the alteration is Q225H, V238I, T241 and T240G. The polypeptide further comprises at least one additional altered amino acid at positions of 97, 99, 100, 118, 119, 121, 123, 126, 127, 128, 130, 132, 134, 135, 140, 147, 151, 153, 163, 168, 173, 174, 177, 179, 182, 187, 193, 206, 207, 212, 217 or 621 of the amino acid sequence having SEQ ID NO: 2; and at least one additional altered amino acid, where the alteration is V971, Y99F, S100G, V118T, N119E, I121M, E12 3Q, Q12 6E, F12 7Y, I12 8L, E13 0A, VI32A, A134G, S135C, S135V, I14 0L, PI47A, T151I, Q153H, V163T, T168A, G17 3A, G17 3S, Q174E, N17 7E, I17 9L, VI82A, V182N, T18 7C, L193V, N206D, P207V, L212M, T217L, L621F or L621T. The polypeptide is an amino acid sequence comprising SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 10, SEQ ID NO: 12, or SEQ ID NO: 14; or an amino acid comprising SEQ ID NO: X having (i) identical residues percentage of at least 70% identity, preferably 75%, 80%, 90%, 95%, 98% or 99%, compared to the length of SEQ ID NO: 4, 6, 8, 10, 12 or 14, and (ii) identical residues percentage of at least 70%, preferably 75%, 80%, 90%, 95%, 98% or 99%, compared to the length of SEQ ID NO: X, (where the above sequences are not defined). The isolated host cell is Trichoderma, Aspergillus, Neurospora, Humicola, Penicillium, Fusarium, Thermomonospora, Bacillus, Pseudomonas, Escherichia, Clostridium, Cellulomonas, Streptomyces, Yarrowia, Pichia, and Saccharomyces, preferably Trichoderma reesei, Trichoderma viride, Trichoderma koningii, Aspergillus niger, Aspergillus nidulans, Aspergillus wentii, Aspergillus oryzae, Aspergillus phoenicis, Neurospora crassa, Humicola grisea, Penicillium pinophilum, Penicillium oxalicum, Escherichia coli, Clostridium acetobutylicum, Clostridium saccharolyticum, Clostridium beijerinckii, and/or Clostridium butylicum.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The production of biofuel from the biomass comprises placing the biomass in suspension in aqueous phase to hydrolyze, adding simultaneously the enzymatic composition acting on lignocellulosic biomass and fermentative organism, and separating the biofuel from the fermentation wort. EXAMPLE - No suitable example given.