Cloning of a maltogenic alpha‐amylase from Bacillus stearothermophilus

We have cloned and expressed a novel maltogenic alpha‐amylase from B. stearothermophilus on plasmid in B. subtilis. Originally the plasmid was very unstable in the absence of selection, but was stabilized due to a spontaneous, copy number reducing mutation. The promoter region and the extension of the gene have been analysed, and a provisional DNA sequence has been determined. The N‐terminal of the mature amylase has been determined and shown to be in accordance with signal peptidase processing after a typical Gram‐positive signal sequence of 33 amino acids.