TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Polypeptide: The isolated polypeptide comprises amino acids 20 to 456 of SEQ ID NO. 3. It is encoded by nucleotides 58 to 1368 of fully defined 1660 bp (SEQ ID NO. 2) given in the specification. It comprises amino acids 1 to 546 of SEQ ID NO. 3. It also comprises an amino acid sequence at least 95% identical to amino acids 507 to 546 of SEQ ID NO. 3, where the polypeptide has cellobiohydrolase activity. It comprises amino acids 507 to 546 of SEQ ID NO. 3. It is encoded by nucleotides 1519 to 1638 of SEQ IDNO. 2. It comprises amino acids 20-546 of SEQ ID NO. 3. It also comprises an amino acid sequence at least 95% identical to amino acids 457 to 546 of SEQ ID NO. 3, where the polypeptide has cellulose binding activity. It comprises amino acids 457 to 546 of SEQ ID NO. 3. It is encoded by nucleotides 1369 to 1638 of SEQ ID NO. 2. It comprises amino acids 20-546 of SEQ ID NO. 3. It comprises SEQ ID NO. 3. The polypeptide is encoded by SEQ ID NO. 2. It comprises a fragment having at least about 100 contiguous amino acids of SEQ ID NO. 3. It comprises a fragment having at least about 200 contiguous amino acids of SEQ ID NO. 3. It also comprises fragment having at least about 50 contiguous amino acids of SEQ ID NO. 3, where the polypeptide has cellulose binding activity. The polypeptide is produced by a marine fungoid protist species selected from Schizochytrium aggregatum, Schizochytrium limacinum, Thraustochytrium visurgense, Thraustochytrium motivum, Thraustochytrium multirudimentale, Thraustochytrium aggregatum, Thraustochytrium roseum, Thraustochytrium striatum, Ulkenia minuta, Ulkenia visurgensis, Schizochytrium octosporum, and Diplophrys marina. It further comprises a heterologous polypeptide. The heterologous polypeptide is selected from the group consisting of a pre or pro sequence, a signal sequence an affinity purification peptide, a heterologous saccharolytic peptide, a heterologous tethering peptide, and a combination of one or more of the heterologous polypeptides. The signal sequence comprises amino acids 1-19 of SEQ ID NO. 3. The marine fungoid protist species is Schizochytrium aggregatum. Preferred Polynucleotide: The polynucleotide comprises the nucleic acid sequence of SEQ ID NO. 2. It comprises nucleotides 58 to 1368 of SEQ ID NO. 2. It comprises a nucleic acid sequence encoding amino acids 20 to 546 of SEQ ID NO. 3. It comprises nucleotides 58-1640 of SEQ ID NO. 4. The nucleic acid sequence is codon-optimized for Saccharomyces cerevisiae and encodes for a polypeptide comprising amino acids 20 to 456 of SEQ ID NO. 3. It also comprises a nucleic acid sequence at least 70% identical to a nucleic acid sequence encoding a polypeptide comprising amino acids 507 to 546 of SEQ ID NO. 3, where the polypeptide has cellulose binding activity. It comprises a nucleic acid sequence encoding amino acids 507 to 546 of SEQ ID NO. 3. It comprises nucleotides 1519 to 1638 of SEQ ID NO. 2. It comprises a nucleic acid sequence encoding amino acids 19 to 546 of SEQ ID NO. 3. It also comprises a nucleic acid sequence at least 70% identical to a nucleic acid sequence encoding a polypeptide comprising amino acids 457 to 546 of SEQ ID NO. 3, where the polypeptide has cellulose binding activity. It comprises a nucleic acid sequence encoding amino acids 457 to 546 of SEQ ID NO. 3. It comprises nucleotides 1369 to 1638 of SEQ ID NO. 2. It comprises a nucleic acid sequence encoding amino acids 20 to 546 of SEQ ID NO. 3. It comprises a nucleic acid sequence encoding SEQ ID NO. 3. It comprises nucleotides 1 to 1638 of SEQ ID NO. 2. It further comprises a promoter sequence. The promoter sequence comprises nucleotides 2372-3871 of fully defined 7509 bp (SEQ ID NO. 1) given in the specification or nucleotides 2871-3871 of SEQ ID NO. 1. It further comprises a terminator sequence. The terminator sequence comprises nucleotides 5627-6627 of SEQ ID NO. 1 or nucleotides 5627-6127 of SEQ ID NO. 1. Preferred Vector: The vector is a yeast episomal plasmid. The yeast episomal plasmid is pMU506. The backbone of the vector is a yeast integrative plasmid. The yeast integrative plasmid is pMU562. Preferred Cell: The host cell is of a yeast organism. The yeast organism is selected from the group consisting of Saccharomyces cervisiae, Kluveromyces lactus, Kluveromyces marxianus, Schizzosaccharomyces pombe, Candida albicans, Pichia pastoris, Pichia stipitis, Yarrowia lipolytica, Hansenula polymorpha, Phaffia rhodozyma, Candida utilis, Arxuia adeninivorans, Debaryomyces hansenii, Debaryomyces polymorphus and Schwanniomyces occidentalis. The yeast organism is Saccharomyces cerevisiae. The host cell is a thermophilic or mesophilic bacterial organism. The expression of the polypeptide results in the host cell exhibiting higher cellobiohydrolase activity as compared to the original host strain or to the host strain transformed with empty vector. It further comprises one or more heterologously expressed endoglucanase polypeptides. It further comprises one or more heterologously expressed beta-glucosidase polypeptides. It further comprises one or more heterologously expressed exoglucanase polypeptides. It further comprises at least one or more heterologously expressed endoglucanase polypeptides and/or at least one or more heterologously expressed beta-glucosidase polypeptides and/or at least one or more heterologously expressed exoglucanase polypeptides. The endoglucanase polypeptide is selected from the group consisting of Eg1, Eg2, Eg3, Eg4 and Eg5. The beta-glucosidase polypeptide is selected from the group consisting of S. fibuligera Bgl1 and Bgl2. The exogluconase polypeptide is selected from the group consisting of T. emersonii cellobiohydrolase I (Cbh1), T. reesei Cbh1, T. reesei cellobiohydrolase II (Cbh2), Chaetomium thermophilum Cbh1, and Neosartorya fischeri Cbh1. Preferred Method: In converting lignocellulosic biomass to ethanol, the lignocellulosic biomass is selected from the group consisting of 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, recycled wood pulp fiber, paper sludge, sawdust, hardwood, sofiwood, and combinations. The lignocellulosic biomass is switch grass, hardwood or soft wood. In digesting a cellulosic substrate, the cellulosic substrate is selected from the group consisting of Avicel, microcrystalline cellulose, phosphoric acid swollen cellulose (PASC), and hardwood. SPECIFIC SEQUENCES - Specifically claimed are isolated polypeptide of Schizochytrium aggregatum Cbh1 comprising 555 amino acids (SEQ ID NO. 3) encoded by 1660-7509 bp (SEQ ID NO. 1 and 2). All sequences are fully defined in the specification.    EXAMPLE - No suitable example given.