FERULIC ACID ESTERASE FROM ASPERGILLUS-NIGER - PURIFICATION AND PARTIAL CHARACTERIZATION OF 2 FORMS FROM A COMMERCIAL SOURCE OF PECTINASE

Two forms of ferulic acid esterase from Aspergillus niger have been is olated from a commercial source of pectinase. One, designated I, has a M(r) of 132 000, is probably dimeric, and has a pI of 3.0. The second , designated II, was partially purified and is monomeric (M(r) 29000), with a pI of 3.6. Both enzymes were free of pectinase and xylanase ac tivity and released ferulic acid from methyl ferulate. In association with a xylanase, they also released ferulic acid from destarched wheat bran. Ferulic acid esterase II released a small amount of ferulic aci d (0.09 unit/mg of protein) in the absence of xylanase. The enzymes ha d different specificities for a range of methyl ester derivatives of c innamoyl and benzoyl acids, acetylated xylan and p-nitrophenyl acetate .