Escherichia coli strains expressing different nitrilases transformed nitriles or KCN. Six nitrilases (from Aspergillus niger (2), A. oryzae, Neurospora crassa, Arthroderma benhamiae, and Nectria haematococca) were arylacetonitrilases, two enzymes (from A. niger and Penicillium chrysogenum) were cyanide hydratases and the others (from P. chrysogenum, P. marneffei, Gibberella moniliformis, Meyerozyma guilliermondi, Rhodococcus rhodochrous, and R. ruber) preferred (hetero)aromatic nitriles as substrates. Promising nitrilases for the transformation of industrially important substrates were found: the nitrilase from R. ruber for 3-cyanopyridine, 4-cyanopyridine and bromoxynil, the nitrilases from N. crassa and A. niger for (R,S)-mandelonitrile, and the cyanide hydratase from A. niger for KCN and 2-cyanopyridine.
- MeSH
- aminohydrolasy chemie genetika metabolismus MeSH
- dehydratasy chemie genetika metabolismus MeSH
- Escherichia coli genetika MeSH
- fungální proteiny chemie genetika metabolismus MeSH
- genom fungální * MeSH
- genomika MeSH
- houby enzymologie genetika MeSH
- rekombinantní proteiny chemie genetika metabolismus MeSH
- sekvenční analýza DNA MeSH
- sekvenční homologie aminokyselin MeSH
- sekvenční seřazení MeSH
- substrátová specifita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The aim of this work was to determine the ability of rhodococci to transform 3,5-dichloro-4-hydroxybenzonitrile (chloroxynil), 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil), 3,5-diiodo-4-hydroxybenzonitrile (ioxynil) and 2,6-dichlorobenzonitrile (dichlobenil); to identify the products and determine their acute toxicities. Rhodococcus erythropolis A4 and Rhodococcus rhodochrous PA-34 converted benzonitrile herbicides into amides, but only the former strain was able to hydrolyze 2,6-dichlorobenzamide into 2,6-dichlorobenzoic acid, and produced also more of the carboxylic acids from the other herbicides compared to strain PA-34. Transformation of nitriles into amides decreased acute toxicities for chloroxynil and dichlobenil, but increased them for bromoxynil and ioxynil. The amides inhibited root growth in Lactuca sativa less than the nitriles but more than the acids. The conversion of the nitrile group may be the first step in the mineralization of benzonitrile herbicides but cannot be itself considered to be a detoxification.
- MeSH
- amidohydrolasy metabolismus MeSH
- amidy metabolismus toxicita MeSH
- benzamidy metabolismus MeSH
- biotransformace MeSH
- dehydratasy metabolismus MeSH
- herbicidy chemie metabolismus MeSH
- hydrolýza MeSH
- jodbenzeny metabolismus MeSH
- kořeny rostlin účinky léků růst a vývoj metabolismus MeSH
- nitrily chemie metabolismus toxicita MeSH
- Rhodococcus metabolismus MeSH
- salát (hlávkový) účinky léků růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
