Thermostable (1,3-1,4)-.beta.-glucanase

A thermostable hybrid (1,3-1,4)-.beta.-glucanase of the general formula

• A-M
• where A is a polypeptide consisting of a 16 to 107 amino acid sequence which is at least 75% identical to the amino acid sequence of the N-terminal part of the Bacillus amyloliquefaciens (1,3-1,4)-.beta.-glucanase and M is a polypeptide consisting of a 107 to 198 amino acid sequence which is at least 75% identical to the amino acid sequence of the C-terminal part of the Bacillus macerans (1,3-1,4)-.beta.-glucanase said hybrid (1,3-1,4)-.beta.-glucanase retaining at least 50% of its activity after 10 minutes or more of incubation in 5-10 mM CaCl.sub.2, 20-40 mM Na-acetate at a pH of 6.0 or lower and at a temperature of 65.degree. C. or higher, the incubated solution having an enzyme concentration range from 0.05 mg to 1 mg (1,3-1,4)-.beta.-glucanase per ml, the activity of (1,3-1,4)-.beta.-glucanase being understood as the ability of the enzyme to hydrolyze .beta.-glycosidic linkages in (1,3-1,4)-.beta.-glucans, the hybrid (1,3-1,4)-.beta.-glucanase being more thermostable than any of the glucanases encoded by the parental (1,3-1,4)-.beta.-glucanase genes.