TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation: (I) is prepared by incubating (V) genetically engineered to express a polynucleotide of (I), further involves isolating the GuxA polypeptide from the incubated host cells. The host cell is genetically engineered to express a selectable marker, and further comprises a polynucleotide molecule encoding one or more polypeptide molecules chosen from the glycoside hydrolase family of proteins. The glycoside hydrolase is a thermostable glycoside hydrolase.Preferred Polypeptide: (I) has at least 90% sequence identity with (S1) to (S5). (I) preferably has a sequence of (S1). (I) is further defined as being encoded by a fully defined sequence of 3687 nucleotides (S6) as given in the specification. The nucleotide sequence encoding (I) is operably linked to a transcriptional or translational regulatory sequence which comprises transcriptional promoter or enhancer.Preferred Composition: In (II), the GuxA peptide comprises a linker and a signal peptide. The GH6 or GH12 catalytic domain of the GuxA peptide is further defined as having a length of about 420-425 or 225-235 amino acids. CBD type 3 or type 2 of (I) is further defined as having a length of about 145-155 or 95-105 amino acids. GH6 or GH12 catalytic domain further has a sequence of (S2) or (S4). CBD type 3 further has a sequence of (S3) or (S5). (I) is further defined as comprising a nucleic acid sequence having at least 90% identity to the nucleic acid sequence encoding an amino acid sequence of (S1)-(S5), or nucleic acid sequence of (S6). (I) is further defined as comprising a nucleic acid sequence encoding a heterologous protein (peptide tag) in frame with the GuxA peptide of (II). The peptide tag is 6-His, thioredoxin, hemaglutinin, glutathione-S-transferase (GST), or OmpA signal sequence tag. The heterologous protein is a substrate targeting moiety.Preferred Industrial Mixture: (III) further comprises a detergent.Preferred Host Cell: (V) is genetically engineered to express the polynucleotide molecule of (I). (V) is a fungi, plant or bacterial cell.Preferred Fusion Protein: In (IV), the heterologous peptide is an agent that promotes polypeptide oligomerization. The agent is a leucine zipper.Preferred Antibody: (VI) is a polyclonal antibody or monoclonal antibody. ADMINISTRATION - (II) is administered by oral, parental, intravenous, intramuscular, intrastemal, infusion or topical route. No specific dosage detail is given.    EXAMPLE - Genomic DNA was isolated from Acidothennus cellulolyticus and purified by banding on cesium chloride gradients. Genomic DNA was partially digested with Sau 3A and separated on agarose gels. DNA fragments in the range of 9-20 kilobase pairs were isolated from the gels. This purified Sau 3A digested genomic DNA was ligated into the Bam H1 acceptor site of purified EMBL3 lambda phage arms. Phage DNA was packaged and plated with Escherichia coli LE392 in top agar which contained the soluble cellulose analog, carboxymethylcellulose (CMC). The plates were incubated overnight (12-24 hours ) to allow transfection, bacterial growth and plaque formation. Plates were stained with Congo Red followed by destaining with 1M NaCl. Lambda plaques harboring endoglucanase clones showed up as unstained plaques on a red background. Lambda clones which screened positive on CMC Congo Red plates were purified by successive rounds of picking, plating and screening. Individual phage isolates were named SL-1, SL-2, SL-3 and SL-4. Subsequent subcloning efforts employed the SL-3 clone which contained an approximately 14.2 kb fragment of A.cellulolyticus genomic DNA. Template DNA was constructed using a 9 kb BamH1 fragment obtained from the 14.2 kb lambda clone SL-3 prepared from A.cellulolyticus genomic DNA. The 9-kb BamHI fragment from SL-3 was subcloned into pDR540 to generate a plasmid NREL501. NREL501 was first sequenced by the primer walking method. NREL501 was then subcloned into pUC19 using restriction enzymes PstI and EcoRI and transformed into E.coli XL1-blue for the production of template DNA for sequencing. Each subclone was sequenced from both forward and reverse directions. Sequencing data from primer walking and subclones were assembled together to verify that all SL3 regions had been sequenced from both strands. An open reading frame (ORF) was found in the 9-kb BamHI fragment, and was about 3687 nucleotides in length.