A process for the enzymatic preparation of 7-aminocephalosporanic acid

摘要

A process for the production of an E.coli strain producing high yields of 7 beta -(4-carboxybutanamido) cephalosporin acylase, comprises: (a) digesting the DNA of a microorganism whose DNA includes the sequence encoding 7 beta -(4-carboxybutanamido) cephalosporin acylase, and forming a plasmidic library; (b) transforming, with the sequences in the plasmidic library, an auxotrophic E. coli host; (c) selecting for transformed E. coli hosts containing the acylase sequence by growth on a suitable medium; (d) isolating the vector containing the acylase sequence, digesting the vector, and ligating the DNA sequences obtained into an E. coli vector under control of an E. coli promoter; (e) repeating selection procedure of step (c); (f) using the vectors from the selected E.coli hosts to transform an E.coli host lacking substantial beta -lactamase activity. 7-Aminocephalosporanic acid and its derivatives can be prepared by reaction of substrates like 7 beta -(4-carboxybutanamido) cephalosporanic acid with 7 beta -(4-carboxybutanamido) cephalosporin acylase produced by the E.coli strain produced by the above process.