Deacetylation of PS-5, a new beta-lactam compound, I. Microbial deacetylation of PS-5.

PS-5 was deacetylated to NS-5 (deacetylated PS-5) by l-amino acid acylase from porcine kidney and D-amino acid acylase from Streptomyces olivaceus but not by l-amino acid acylase from Aspergillus sp. Using PS-5, N-chloroacetyl-l-phenylalanine and N-chloroacetyl-D-valine as substrates, acylase producers were screened among facultative methanol-assimilating bacteria. Most of the microbes tested were active and could be classified into two groups of l-acylase producers and L-& D-acylase producers. Pseudomonas sp. 1158 which deacetylated the three substrates was chosen for further study. Cells of the bacterium entrapped in polyacrylamide gel and its acylase activities immobilized on DEAE-Sephadex were found to be useful for conversion of PS-5 to NS-5.