DEACETYLATION OF PS-5, A NEW β-LACTAM COMPOUND: I. MICROBIAL DEACETYLATION OF PS-5

PS-5 was deacetylated to NS-5(deacetylated PS-5) by L-aminoa cid acylase from porcine kidney and D-amino acid acylase from Streptomyce oslivaceus but not by L-aminoa cid 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.