Abstract Multimeric uridine phosphorylase (UP) and purine nucleoside phosphorylase (PNP) of Bacillus subtilis have been expressed from genes cloned in Escherichia coli, purified, characterized, immobilized and stabilized on solid support. A new immobilization strategy has been developed for UP onto Sepabeads coated with polyethyleneamine followed by cross-linking with aldehyde-dextran. PNP has been immobilized onto glyoxyl- ...