BIOCONVERSION OF CEPHALOSPORIN-C WITH D-AMINO-ACID OXIDASE FROM THE YEAST RHODOSPORIDIUM TORULOIDES

A D-amino acid oxidase-producing yeast, Rhodosporidium toruloides CCRC 20306, was used to convert cephalosporin C (Ceph C) into alpha-ketoad ipyl cephalosporanic acid. A part of Ceph C could be directly converte d into glutaryl-7-aminocephalosporanic acid (GL-7-ACA) by permeated ce lls of CCRC 20306. There were unknown side products formed during the conversion. The side products could be substantially reduced in amount by heating the cell extract containing D-alanine at 55 degrees C for 5 min for five cycles prior to the conversion. Esterase activity prese nt in the cell extract, which might be one of the causes of the side r eaction, was greatly diminished by heat treatment.