TECHNOLOGY FOCUS - BIOLOGY - Preparation: No preparation method is given. Preferred Method: The method-I further comprises isolating the produced variant. The method-II further comprises: one or more of killing the host cells after the culturing step, filtering the collected cell culture supernatant to remove cell debris, and subjecting the cell culture supernatant to ultrafiltration or other steps to enrich or concentrate the CBH variant; and contacting the cell culture supernatant with a lignocellulosic biomass substrate. Preferred Components: The parent CBH polypeptide has at least 90% sequence identity to SEQ ID NO:3. The variant comprises at least one amino acid substitution at a position comprising A414, G22, R394, T417, P227, T255, V403, F280, E337, P258, T332, T296, N49, Y493, S196, G430, T246, Y247, N307, T356, Y466, S357, Q27, S387, L318, T389, Y303, Y370, K287, T285, N350, D249, F338, S113, Y492, S398, T226, Y371, A316, K346, G340, S342, D368, M374, D179, E236, Y474,G391, F418, F311, R251, T281, V104, L326, A224 and E385, where the position of each amino acid substitution corresponds to SEQ ID NO: 3. At least one amino acid substitution as given in the table 4 of the specification. At least one amino acid substitution comprises: an amino acid substitution at position A414 comprising Phe, Asn, Leu, Met, Trp, Arg, Gly, Lys, Ile, His, Gln, Asp, Cys or Thr; an amino acid substitution at position G22 comprising Asp, Glu, His, Pro, Thr, Phe, Cys, Ala, Trp, Leu, Tyr, Ile, Gln, Met, Lys or Ser; an amino acid substitution at position R394 comprising Glu, Pro, Tyr, Phe, Trp, Gln, Leu, Asn, Thr, Met, Cys, Ala, Ile, Ser, Gly, Arg, Asp or Val; an amino acid substitution at position T417 comprising Trp, Leu, Ile, Phe, Glu, Asp, Lys, Arg, His, Ala, Thr, Val, Tyr, Ser or Gln; an amino acid substitution at position P227 comprising Ile, Trp, Met, Val, Glu, Thr, Leu, Ala or Cys; an amino acid substitution at position T255 comprising Glu, Phe, Leu, Ser, Trp, Pro, Asp, Ile, Asn, Gln, Cys, Arg, Val or Lys; an amino acid substitution at position V403 comprising Thr, Tyr, Asn, Glu, Asp, Met, Ile, Lys, Arg or Val; an amino acid substitution at position F280 comprising Ile, His, Asp, Asn, Val, Trp, Glu, Phe or Ser; an amino acid substitution at position E337 comprising Cys, Val, Gly, Gln, Arg, Ile, Met, Ser or Trp; an amino acid substitution at position P258 comprising Arg, Ile, Lys, Gly, Met, His, Asn, Ser, Leu, Gln or Ala; an amino acid substitution at position T332 comprising Ser, Met, Cys, Tyr, Lys, Gln, Arg or Ala; an amino acid substitution at position T296 comprising Thr, Asp, Glu, Tyr, Asn, Phe, Lys, Trp, Ala, Ser or Leu; an amino acid substitution at position N49 comprising Met, Gln, Leu, Gly, Glu, Asp, Ala, Ser or Pro; an amino acid substitution at position Y493 comprising Glu, Lys, Asn, Asp, Ile, Ala, Val or Phe; an amino acid substitution at position S196 comprising Asp, Val, Glu, Phe, Ala, Lys, Gly, Arg, Leu, Pro, Met or Ile; an amino acid substitution at position G430 comprising Asn, Gln, Ser, Ala, Arg, Leu, Met, Cys, Asp, Ile or Thr; an amino acid substitution at position T246 comprising Lys, Leu, Met, Glu, Trp, Asn, Arg, Ile, Gln, Thr, Phe, Pro or Ser; an amino acid substitution at position Y247 comprising Gln, Thr, Met, Trp, Asp or Phe; an amino acid substitution at position N307 comprising Glu, Arg, Ala, Cys, Asp or His; an amino acid substitution at position T356 comprising Met, Ile or Leu; an amino acid substitution at position Y466 comprising Arg, Cys, Val or Ser; an amino acid substitution at position S357 comprising Ala, Gly, Thr, Arg or Val; an amino acid substitution at position Q27 comprising Ala, Glu, Lys, Val, Thr or Ile; an amino acid substitution at position S387 comprising Lys, Ile, Trp, Gly, Asp, Val or Ala; an amino acid substitution at position L318 comprising Ile, Val or Cys; an amino acid substitution at position T389 comprising Ser, His, Val or Asp; an amino acid substitution at position Y303 comprising Trp, Leu or Phe; an amino acid substitution at position Y370 comprising Arg, Gln, Leu, Gly or Phe; an amino acid substitution at position K287 comprising Glu, Tyr, Asp or Asn; an amino acid substitution at position T285 comprising Arg, Cys, Lys or Gln; an amino acid substitution at position N350 comprising Lys, Asp, Gln, Leu or Ile; an amino acid substitution at position D249 comprising Ala, Gln or Ser; an amino acid substitution at position F338 comprising Asp, Leu or Arg; an amino acid substitution at position S113 comprising Gly, Glu, Asn or Thr; an amino acid substitution at position Y492 comprising Met, His, Ala or Phe; an amino acid substitution at position S398 comprising Ala, Asp or Pro; an amino acid substitution at position T226 comprising Gly, Ala, Cys, Asp, Val or Ser; an amino acid substitution at position Y371 comprising Tyr or Trp; an amino acid substitution at position A316 comprising Ile or Cys; a K346H amino acid substitution; a G340D amino acid substitution; a S342C amino acid substitution; a D368C amino acid substitution; a M374C amino acid substitution; an E236D amino acid substitution; an amino acid substitution at position Y474 comprising Lys, and Trp; a G391Y amino acid substitution; a F418Y amino acid substitution; an amino acid substitution at position F311 comprising Tyr and Val; an R251A amino acid substitution; a T281D amino acid substitution; an amino acid substitution at position V104 comprising Phe and His; an L326I amino acid substitution; an A224Q amino acid substitution and/or an E385Y amino acid substitution. The variant further comprises an additional amino acid mutation at one or both amino acid positions corresponding to S92 and T41 of SEQ ID NO: 3. The additional amino acid mutation is an amino acid substitution comprising S92T and/or T411. The parent CBH polypeptide is a fungal CBH1. The fungal CBH1 comprises Hypocrea jecorina, Hypocrea schweinitzii, Hypocrea orientalis, Trichoderma pseudokoningii, Trichoderma konilangbra, Trichoderma citrinoviride, Trichoderma harzianum, Aspergillus aculeatus, Aspergillus niger, Penicillium janthinellum, Humicola grisea, Scytalidium thermophilum or Podospora anserina. The vector is an expression vector. The host cell is a fungal cell or a bacterial cell. The host cell is a: fungal cell is a filamentous fungal cell comprising Trichoderma reesei, Trichoderma longibrachiatum, Trichoderma viride, Trichoderma koningii, Trichoderma harzianum, Penicillium, Humicola, Humicola insolens, Humicola grisea, Chrysosporium, Chrysosporium lucknowense, Myceliophthora thermophila, Gliocladium, Aspergillus, Fusarium, Neurospora, Hypocrea, Emericella, Aspergillus niger, Aspergillus awamori, Aspergillus aculeatus or Aspergillus nidulans; or a yeast cell comprising Saccharomyces cerevisiae, Schizzosaccharomyces pombe, Schwanniomyces occidentalis, Kluyveromyces lactis, Candida utilis, Candida albicans, Pichia stipitis, Pichia pastoris, Yarrowia lipolytica, Hansenula polymorpha, Phaffia rhodozyma, Arxula adeninivorans, Debaryomyces hansenii, Debaryomyces polymorphus or a Zymomonas mobilis bacterial cell. The host cell expresses the variant of a parent CBH polypeptide encoded by the isolated polynucleotide, vector, or expression vector. The cell culture supernatant is derived from a culture of the host cell, and further comprises one or more additional cellulases or hemicellulases. The host cell further expresses one or more additional cellulases and/or hemicellulases that are present in the cell culture supernatant. The additional cellulases and/or hemicellulases are exogenously expressed in the host cell, endogenously expressed in the host cell and/or mixed with the cell culture supernatant. EXAMPLE - No suitable example given.