Transformoidut prokaryoottiset isäntäsolut

Transformed prokaryotic hosts are provided comprising two or more copies of a DNA sequence stably maintained in their chromosome, said sequence comprising a gene encoding a polypeptide of interest, wherein said copies are separated by endogenous chromosomal DNA sequences. Methods are also provided for producing said transformed host strains. Said transformed host strains are capable of increased production of the polypeptide of interest compared to host strains which already produce said polypeptide. Preferred host strains are Bacillus novo species PB92 which produces a high-alkaline proteolytic enzyme and Bacillus licheniformis T5 which produce a thermostable alpha-amylase, and mutants and variants of said strains. Preferred polypeptide encoding genes are the protease encoding gene originating from Bacillus PB92 and the alpha-amylase encoding gene originating from Bacillus licheniformis strain T5.