Improvement of penicillin G acylase production by using pac gene clone.

The penicillin G acylase gene (pac gene) from Escherichia coli ATCC 9637 has been isolated. It conferred the production of penicillin G acylase upon E. coli HB101 and other enteric bacilli. Restriction enzyme analysis and subcloning studies reveal that the gene is contained within a 2.3 kb HindIII-SmaI DNA fragment. In vitro protein synthesis study suggests a gene product of approximately 90 kDa. By using the genetically engineered bacteria which harbor a novel recombinant plasmid (pGL5) bearing a constitutively expressible pac gene, a 20-fold increased production yield of penicillin G acylase activity was obtained as compared with that produced by the original strain, E. coli ATCC 9637.