TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Variant: The variant comprises an amino acid substitution selected from Phe418Met, Thr246Ser, Thr255Val, and their combination, where the position of each amino acid substitution corresponds to SEQ ID NO. 3. The variant further comprises an amino acid substitution selected from Thr246Pro and Thr246Val. The variant further comprises an amino acid substitution selected from Thr255Asp, Thr255Ile, Thr255Lys, Thr255Pro, and Thr255Arg. The variant further comprises an amino acid substitution selected from Asp241Asn, Gly234Asp, Ser92Thr, Thr41Ile, Gly234Asp, Pro194Val, Asn200Gly or Asn200Arg, Asn49Pro, Tyr247Asp, Thr356Leu, and their combination. The parent CBH polypeptide is a fungal CBH1, where the fungal CBH1 is from Hypocrea jecorina, Hypocrea schweinitzii, Hypocrea orientalis, Trichoderma pseudokoningii, Trichoderma konilangbra, Trichoderma citrinoviride, Trichoderma harzanium, Aspergillus aculeatus, Aspergillus niger, Penicillium janthinellum, Humicola grisea, Scytalidium thermophilum, or Podospora anderina. The parent CBH polypeptide has at least 90% sequence identity to SEQ ID NO. 3. Preferred Vector: The vector is an expression vector. Preferred Host Cell: The host cell is a fungal cell or a bacterial cell. The host cell is selected from a filamentous fungal cell selected from Trichoderma reesei, Trichoderma longibrachiatum, Trichoderma viride, Trichoderma koningii, Trichoderma harzianum, Penicillium, Humicola, Humicola insolens, Humicola grisea, Chrysosporium, Chrysosporium lucknowense, Myceliophthora thermophilia, Gliocladium, Aspergillus, Fusarium, Neurospora, Hypocrea, Emericella, Aspergillus niger, Aspergillus awamori, Aspergillus aculeatus, and Aspergillus nidulans; a yeast cell selected from Saccharomyces cervisiae, Schizzosaccharomyces pombe, Schwanniomyces occidentalis, Kluveromyces lactus, Candida utilis, Candida albicans, Pichia stipitis, Pichia pastoris, Yarrowia lipolytica, Hansenula polymorpha, Phaffia rhodozyma, Arxula adeninivorans, Debaryomyces hansenii, and Debaryomyces polymorphus; and 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. Preparation (claimed): Producing a variant CBH polypeptide comprises culturing a host cell of (3) in a suitable culture medium under suitable conditions to produce the variant. The method further comprises isolating the produced variant. Preferred Method: In the method for hydrolyzing a cellulosic substrate, the cellulosic substrate is of a lignocellulosic biomass is selected from grass, switch grass, cord grass, rye grass, reed canary grass, Miscanthus, sugar-processing residues, sugarcane bagasse, agricultural wastes, rice straw, rice hulls, barley straw, corn cobs, cereal straw, wheat straw, canola straw, oat straw, oat hulls, corn fiber, stover, soybean stover, corn stover, forestry wastes, wood pulp, recycled wood pulp fiber, paper sludge, sawdust, hardwood, softwood, and their combination. The method of producing a cell culture supernatant comprising a CBH variant further comprises one or more of the following: 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. The host cell further expresses one or more additional cellulases and/or hemicellulases, where the one or more additional cellulases and/or hemicellulases are present in the cell culture supernatant. One or more additional cellulases and/or hemicellulases are: exogenously expressed in the host cell, endogenously expressed in the host cell, mixed with the cell culture supernatant, or their combination. The method further comprises contacting the cell culture supernatant with a lignocellulosic biomass substrate. Preferred Cell Culture Supernatant: The cell culture supernatant is derived from a culture of a host cell of (3). The cell culture supernatant further comprises one or more additional cellulases or hemicellulases. EXAMPLE - No suitable example given.