NEW MATERIAL:The DNA fragment carrying the gene information concerning the production of the acylase for a cephalosporin compound and obtained by incising the whole DNA of a bacterium belonging to Comamonas genus with a restriction enzyme.

USE: A novel DNA fragment to be introduced into the cell of Escherichia coil for the industrial production of cephalosporin acylase.

PREPARATION: Whole DNA is extracted from the cell of a bacterium belonging to Comamonas genus, i.e. Comamonas SY-77-1 (FERM-P-2410), and is incised with restriction enzyme. The cephalosporin acylase can be produced using the obtained DNA fragment as follows. A vector DNA fragment is incised and opened with a restriction enzyme, and the above DNA fragment is integrated to the incised site to obtain a recombinant DNA. The DNA is introduced into the cell of Escherichia coil, and the strain having cephalosporin acylase activity is separated, cultured, and then made to react with the compound of formula I (R is COOH or COCOOH; X is H, OH, OCOCH3, etc.) to obtain the compound of formula II.