Assay for the enzymic hydrolysis of penicillin and acylhydroxamates

A rapid and easily reproducible assay for penicillin acylase and aliphatic amidase activity is described. The method, which is based on the colorimetric estimation of proton release, is very sensitive and rates as low as 0.5 nmoles/minute can be measured readily. Determination of the kinetic constants of the enzymes gave results as good as or better than standard procedures.