Isolation and purification of an enzyme hydrolyzing ochratoxin A from <Emphasis Type="Italic">Aspergillus niger</Emphasis> |
| |
Authors: | Luís Abrunhosa Armando Venâncio |
| |
Institution: | (1) IBB- Institute for Biotechnology and Bioengineering, Centre for Biological Engineering, Universidade do Minho, Campus de Gualtar, Brague, 4710-057, Portugal;(2) Departamento de Engenharia Biológica, Universidade do Minho, Campus de Gualtar, Brague, 4710-057, Portugal |
| |
Abstract: | Ochratoxin A is a mycotoxin produced by several Aspergillus and some Penicillium species which may be present in food and feed products. It can be enzymatically hydrolyzed into ochratoxin α and l-β-phenylalanine, thereby decreasing its toxicity. The ochratoxin A degradation capacity of Aspergillus niger is well known and here we report the isolation and purification of a novel enzyme from A. niger that hydrolyzes this mycotoxin. A wheat germ medium supplemented with ochratoxin A was used to produce the enzyme, which
was purified from culture filtrate by acetone precipitation and anion exchange chromatography. An overall purification of
2.5-fold with a recovery of 68% and a final specific activity of 36 U/mg was obtained. The enzyme is a metalloenzyme as it
was inhibited at 10 mM EDTA, whereas PMSF had no effect. The ochratoxin A hydrolytic enzyme presented a V
max of 0.44 μM/min and a K
m of 0.5 mM when the reaction was carried out at pH 7.5 and 37°C. |
| |
Keywords: | Aspergillus niger Carboxypeptidase Degradation Ochratoxin A Ochratoxin α |
本文献已被 PubMed SpringerLink 等数据库收录! |
|