Description:
<jats:title>Abstract</jats:title><jats:p>The <jats:italic>bg</jats:italic>/M gene DNA coding for a thermostable beta‐1.3,1.4‐glucanase of <jats:italic>Bacillus macerans</jats:italic> E138 was isolated by direct shot‐gun cloning into <jats:italic>Escherichia coli</jats:italic> using plasmid pBR322 as a vector. By deletion analysis the <jats:italic>bg</jats:italic>/M coding region was located within a 1.0 kb region of the cloned <jats:italic>Bacillus</jats:italic> DNA fragment. In <jats:italic>E. coli</jats:italic>, plasmid pBGLM12/2 containing the <jats:italic>B. macerans bg</jats:italic>/M gene gave rise to a beta‐glucanase expression 40 times higher than that of the <jats:italic>B. macerans</jats:italic> gene donor. The molecular weight of beta‐glucanase, isolated either from <jats:italic>E. coli</jats:italic> cells or from the culture filtrate of <jats:italic>B. macerans</jats:italic>, was in the range of 24 kD. The enzymes purified from <jats:italic>E. coli</jats:italic> or from the culture filtrate of <jats:italic>B. macerans</jats:italic>, had a halflife of about 40 min at 65 °C. This indicated an increased temperature stability of the <jats:italic>B. macerans</jats:italic> enzyme in comparison to other <jats:italic>Bacillus</jats:italic>‐beta‐glucanases.</jats:p>