Purification and characterization of a novel esterase induced by growth of Aspergillus niger on sugar-beet pulp

Biotechnol Appl Biochem. 1996 Jun;23(3):255-62.


An inducible esterase has been isolated from a liquid culture of Aspergillus niger grown on sugar-beet pulp. The enzyme was active on methyl esters of cinnamic acids, caffeic > p-coumaric > ferulic, and is therefore termed a cinnamoyl esterase. The enzyme was not active on methyl sinapinate, a good substrate for ferulic acid esterase III, which was purified previously from A. niger [Faulds and Williamson (1994) Microbiology 140, 779-787]. With methyl caffeate as substrate the enzyme had temperature and pH optima of 50 degrees C and 6.0 respectively, and a specific activity of 96.9 units per mg of protein. The purified protein (native molecular mass 145 000 Da) gave a single heavily stained band on SDS/PAGE, suggesting the protein was a dimer, and seemed to be heavily glycosylated. Isoelectric focusing gave a single band corresponding to a pl of 4.80. The pure enzyme was free of other carbohydrase activities. The activity of the pure enzyme was inhibited by more than 99% after treatment with the serine-specific protease inhibitor aminoethylbenzenesulphonylfluoride (1 mM) for 12 h. The enzyme was capable of releasing ferulic acid from sugar beet pulp.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Sulfate / chemistry
  • Aspergillus niger / enzymology*
  • Aspergillus niger / growth & development
  • Caffeic Acids / chemistry
  • Caffeic Acids / metabolism
  • Carbohydrates
  • Cinnamates / chemistry
  • Cinnamates / metabolism
  • Coumaric Acids / chemistry
  • Coumaric Acids / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Esterases / isolation & purification*
  • Esterases / metabolism
  • Glycosylation
  • Isoelectric Focusing
  • Molecular Weight
  • Propionates
  • Structure-Activity Relationship
  • Substrate Specificity
  • Sulfones / chemistry
  • Trypsin Inhibitors / chemistry
  • Ultrafiltration


  • Caffeic Acids
  • Carbohydrates
  • Cinnamates
  • Coumaric Acids
  • Propionates
  • Sulfones
  • Trypsin Inhibitors
  • cinnamic acid
  • 4-(2-aminoethyl)benzenesulfonylfluoride
  • ferulic acid
  • Esterases
  • p-coumaric acid
  • Ammonium Sulfate
  • caffeic acid