Identification and characterization of an acetyl esterase from Paenibacillus sp. XW-6-66 and its novel function in 7-aminocephalosporanic acid deacetylation.

Abstract

To obtain a new acetyl esterase from Paenibacillus sp. XW-6-66 and apply the enzyme to 7-aminocephalosporanic acid (7-ACA) deacetylation. The acetyl esterase AesZY was identified from Paenibacillus sp. XW-6-66, and its enzymatic properties were investigated. With the putative catalytic triad Ser114-Asp203-His235, AesZY belongs to the Acetyl esterase (Aes) family which is included in the α/β hydrolase superfamily and contains the consensus Gly-X-Ser-X-Gly motif. The maximum activity of AesZY was detected at pH 8.0 and 40°C. AesZY was stable at different pH values ranging from 5.0 to 12.0, and was tolerant to several metal ions. Furthermore, the deacetylation activity of AesZY toward 7-ACA was approximately 7.5U/mg, and the Kcat/Km value was 2.04s-1mM-1. Our results demonstrate the characterization of a new acetyl esterase belonging to the Aes family with potential biotechnological applications.