Bacillus sphaericus V-penicillin acylase. II. Isolation and characterisation

Bacillus sphaericus (strain NCTC 10338) produces an intracellular V-penicillin acylase which has been isolated and partially purified after lysozyme treatment. The acylase hydrolyses V-penicillin and V-cephalosporin but not G-penicillin and ampicillin. Optimal activity occurred at 40–60°C and pH 6.8. The system showed some characteristics of an SH-enzyme and was inhibited by phenoxyacetic acid (non-competitive, Ki =30 mM) and 6-aminopenicillanic acid (competitive, Ki =9 mM). The Km for V-penicillin was 140 mM.