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 alpha and L: -beta-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 microM/min and a K (m) of 0.5 mM when the reaction was carried out at pH 7.5 and 37 degrees C.
journal_name
Biotechnol Lettjournal_title
Biotechnology lettersauthors
Abrunhosa L,Venâncio Adoi
10.1007/s10529-007-9479-2subject
Has Abstractpub_date
2007-12-01 00:00:00pages
1909-14issue
12eissn
0141-5492issn
1573-6776journal_volume
29pub_type
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