NOVELTY - A gene encoding bacterial laccase comprising (a) a 1320 base pair sequence (SEQ ID NO: 1) fully defined in the specification, (b) base pair sequence of SEQ ID NO: 1, in which one or more nucleotides are substituted, added or deleted, and encoding proteins with same functions, or (c) nucleotide sequence encoding protein comprising a 439 amino acid sequence (SEQ ID NO: 2) fully defined in the specification, is new.    USE - The gene is useful for encoding bacterial laccase which is used for de-colorizing azo dye (claimed).    ADVANTAGE - The bacterial laccase has excellent stability even at pH of 6-8, and improved shelf-life period of 73 minutes at 45 degrees C.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) bacterial laccase encoded by the above-mentioned gene, comprising amino acid sequence of SEQ ID NO: 2, and amino acid of sequence SEQ ID NO: 2, in which one or more amino acid residues are substituted, added or deleted, and encoding proteins with same functions; (2) recombinant expression vector, comprising the above-mentioned gene; (3) host comprising the above-mentioned gene; and (4) method of preparing the vector, involves amplifying the gene using primers (P1) and (P2) by PCR, linking the amplified product to pMD18-T plasmid to obtain recombinant vector, introducing the obtained vector into Escherichia coli DH1 alpha , screening positive clones to analyze sequence, selecting the clone having a corresponding sequence to obtain pMD18-T recombinant plasmid with bacterial laccase gene (lac15), double digesting the recombinant plasmid and pET22 plasmid using NdeI and XhoI, ligating the obtain gene sequence with pET22b plasmid, introducing the obtained product into competent cell of E.coli BL21(DE3), and screening the positive clones to obtain engineering bacterial strain with lac gene E.coli BL21(DE3)/lac15, where the primer (P1) comprises 5'-catatgaacaggcgagacttcctgg-3', and primer (P2) comprises 5'-ctcgagtgcgacctccacccaggtct-3'.