A gene encoding the mannanase of Bacillussubtilis WL-7, which had been isolated from Korean soybeanpaste, was cloned into Escherichia coli, and the gene productwas purified from the culture filtrate of the recombinantE. coli. This mannanase gene, designated manA, consisted of1,086 nucleotides, encoding a polypeptide of 362 amino acidresidues. The deduced amino acid sequence was highlyhomologous to those of mannanases belonging to the glycosylhydrolase family 26. The molecular mass of the purifiedmannanase was 38 kDa as estimated by SDS-PAGE. Theenzyme had a pH optimum at 6.0 and a temperature optimumat 55oC. The enzyme was active on locust bean gum, konjak,guar gum, and lichenan, while it did not exhibit activitytowards yeast mannan, laminarin, carboxymethylcellulose, β-glucan, xylan, and para-nitrophenyl-β-mannopyranoside.