Abstract: An immobilised hydantoinase containing a divalent metal ion selected from Mn.sup.++, Co.sup.++, Fe.sup.++, Ni.sup.++ and Mg.sup.++ is produced that is useful for the preparation of a D(-)(optionally substituted phenyl)glycine or N-carbamoyl derivative thereof by hydrolysis of a 5-(optionally substituted phenyl)hydantoin in the absence of air. Immobilization is carried out in the presence of the metal iona nd the metal ion stabilizes the hydantoinase and renders it capable of repeated re-use. The divalent metal ion may also be added to a reaction mixture containing the immobilized hydantoinase to minimize reduction of hydantoinase activity during hydrolysis of hydantoin. Cells that produce hydantoinase may be immobilized within or on a support, or hydantoinase separated from cells can be adsorbed on a positively charged polymeric support such as an ion exchange resin or covalently bonded to a polymeric support. A cross-linking agent such as glutaraldehyde may be used in immobilization.

Abstract: A process for the preparation of a compound of formula (I): ##STR1## wherein R.sup.1 is hydrogen, hydroxy, mercapto radical, a substituted or unsubstituted methoxy, ethoxy, methyl, ethyl, methyl thio, or ethylthio radical, a carbamoyloxy, carbamoylthio, C.sub.1-6 alkanoyloxy, C.sub.1-6 alkanoylthio, cyano, carboxy or carbamoyl radical; andR.sup.2 represents an acyl group which comprises hydrolysis of a compound of formula (II): ##STR2## wherein R.sup.1 and R.sup.2 are as defined with respect to formula (I) hereinbefore and R.sup.3 represents benzyl or substituted benzyl; wherein the hydrolysis is catalyzed by a microbial serine proteinase.

Abstract: Novel re-usable water-insoluble penicillin acylase complexes are provided wherein a penicillin acylase is adsorbed on a water-insoluble polymer or co-polymer of methacrylic acid and cross-linked with a water-soluble aldehyde selected from the group consisting of glutaraldehyde, glyoxal and formaldehyde. The complexes are useful in the production of 6-APA from penicillins G and V.