| abstract |
Integration of a product gene (A) in the chromosome of a recipient (e.g. bacterium), which is effected (and selected) using a thy (thymidylate synthase) gene and involved multiple, stepwise individual copies of (A) comprises, (1) general recombination by the mechanism of double crossing over (2CO); (2) use of a cloned they gene, alternately in functional and inactivated form, for integration and selection of (A); (3) detection of 2CO through antibiotic sensitivity and single crossing over (1CO) by antibiotic resistance and (4) confirmation of (A) integration by 2CO by detecting additional gene copies and lack of plasmid DNA. USE/ADVANTAGE - The method is used to produce bacterial strains for stable prodn. of proteins encoded by (A), specifically alpha amylase or neutral protease. Many copies of highly expressed (A) can be introduced, providing transformants of high productivity. These are genetically stable and environmentally safe. |