Process for the fermentative production of deacylated cephalosporins

A process for the production of an N-deacylated cephalosporin compound comprising the steps of:

• (a) fermenting a microbial strain capable of β-lactam production and expressing acyltransferase as well as expandase activity, and optionally acetyltransferase and/or hydroxylase activity, in the presence of a side chain precursor according to formula (1)
• HOOC—X—COOH (1)
• wherein
• X is (CH2)m—CH═A—(CH2)n or (CH2)m—C≡C—(CH2)n, wherein
• m and n each individually are 0, 1, 2 or 3 and m+n=2 or 3, and
• A is CH or N, or
• X is (CH2)p—CH═CH—CH═C—(CH2)q, wherein
• p and q each individually are 0 or 1 and p+q =0 or 1,
• or a salt, ester or amide thereof, said side chain precursor yielding an acyl-6-APA derivative incorporating said precursor, said acyl-6-APA derivative being in situ expanded to the corresponding acyl-7-ADCA derivative, optionally further reacted to the acyl-7-ADAC or acyl-7-ACA derivative, and
• (b) recovering the acyl-7-cephalosporin derivative from the fermentation broth
• (c) deacylating said acyl-7-cephalosporin derivative, and
• (d) recovering the crystalline N-deacylated cephalosporin compound.