Immobilized Streptomyces clavuligerus NP1 cells for biotransformation of penicillin G into deacetoxycephalosporin G

An investigation was conducted to determine whether immobilized resting cel ls of Streptomyces clavuligerus NP1, entrapped on a polymeric matrix, are a ble to perform oxidative ring expansion of benzylpenicillin into deacetoxyc ephalosporin G by virtue of their deacetoxycephalosporin C synthase ("exyan dase") activity. Cells entrapped in polyethyleneimine-barium alginate (1.5% ) were able to sustain activity for at least four 2-h cycles, whereas free resting cells were inactive after the second cycle. Although entrapped cell s exhibited lower oxidative ring expansion activity than free resting cells , immobilization may offer storage stability, recyclability, and operationa l stability for biotransformation of penicillins to cephalosporins, thus co ntributing to the development of a biological means for the production of t he important industrial intermediate 7-aminodeacetoxycephalosporanic acid.