MOLECULAR CLONING OF α-AMYLASE GENE FROM A MUTANT OF BACILLUS LICHENIFORMIS AND ITS EXPRESSION IN VARIOUS STRAINS

Abstract

The amylase gene of a mutant of Bacillus licheniformis was cloned in a plasmid pBR322 by a shotgun method and transferred into Escherichia coli HB101. The transformants produced amylase in the medium. A restriction map of the plasmid carrying amylase gene (pNTK1) was constructed and the smaller plasmids pNTK2 and pNTK3 were made. Ninety-three percent of the amylase activity in the E. coli carrying pNTK3 was found in the periplasmic region. A shuttle vector (pSNK1) was constructed from pNTK3 and pUB110 and it is maintained in both E. coli and Bacillus. The amylase productivity of various Bacillus cells carrying pSNK1 were found to be different from strain to strain. The causes of these differences are discussed.