Esterase that removed acetyl groups from a number of O-acetylated small substrates, such as acetylated xylose, short xylooligosaccharides and cephalosporin C. Has no activity towards polymeric acetylated xylan. Cannot cleave amide linkages. Deacetylation of xylans and xylo-oligosaccharides. cephalosporin C + H2O = acetate + deacetylcephalosporin C + H(+) Homohexamer. Used in the pharmaceutical industry for the chemoenzymatic deacetylation of cephalosporins and the synthesis of novel antibiotics. Belongs to the carbohydrate esterase 7 family.