title: Molecular cloning of alpha-amylase gene from Bacillus amyloliquefaciens and its expression in B. subtilis.
abstract: The gene coding for alpha-amylase from Bacillus amyloliquefaciens was isolated by direct shotgun cloning using B. subtilis as a host. The genome of B. amyloliquefaciens was partially digested with the restriction endonuclease MboI and 2- to 5-kb fragments were isolated and joined to plasmid pUB110. Competent B. subtilis amylase-negative cells were transformed with the hybrid plasmids and kanamycin-resistant transformants were screened for the production of alpha-amylase. One of the transformants producing high amounts of alpha-amylase was characterized further. The alpha-amylase gene was shown to be present in a 2.3-kb insert. The alpha-amylase production of the transformed B. subtilis could be prevented by inserting lambda DNA fragments into unique sites of EcoRI, HindIII and KpnI in the insert. Foreign DNA inserted into a unique ClaI site failed to affect the alpha-amylase production. The amount of alpha-amylase activity produced by this transformed B. subtilis was about 2500-fold higher than that for the wild-type B. subtilis Marburg strain, and about 5 times higher than the activity produced by the donor B. amyloliquefaciens strain. Virtually all of the alpha-amylase was secreted into the culture medium. The secreted alpha-amylase was shown to be indistinguishable from that of B. amyloliquefaciens as based on immunological and biochemical criteria.
mesh_terms: D000681:Amylases / Q000235:genetics*; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D001412:Bacillus subtilis / Q000235:genetics*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000302:isolation & purification; D004274:DNA, Recombinant; D005796:Genes; D005798:Genes, Bacterial; D005779:Immunodiffusion; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D000516:alpha-Amylases / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D004274:DNA, Recombinant; D000681:Amylases; D000516:alpha-Amylases