Document Detail


Characterisation of the substrate specificity of the nitrile hydrolyzing system of the acidotolerant black yeast Exophiala oligosperma R1.
MedLine Citation:
PMID:  19287539     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Abstract/OtherAbstract:
The ;black yeast' Exophiala oligosperma R1 can utilise various organic nitriles under acidic conditions as nitrogen sources. The induction of a phenylacetonitrile converting activity was optimised by growing the strain in the presence of different nitriles and /or complex or inorganic nitrogen sources. The highest nitrile hydrolysing activity was observed with cells grown with 2-cyanopyridine and NaNO(3). The cells metabolised the inducer and grew with 2-cyanopyridine as sole source of nitrogen. Cell extracts converted various (substituted) benzonitriles and phenylacetonitriles. They usually converted the isomers carrying a substituent in the meta-position with higher relative activities than the corresponding para- or ortho-substituted isomers. Aliphatic substrates such as acrylonitrile and 2-hydroxy-3-butenenitrile were also hydrolysed. The highest specific activity was detected with 4-cyanopyridine. Most nitriles were almost exclusively converted to the corresponding acids and no or only low amounts of the corresponding amides were formed. The cells hydrolysed amides only with extremely low activities. It was therefore concluded that the cells harboured a nitrilase activity. The specific activities of whole cells and cell extracts were compared for different nitriles and evidence obtained for limitation in the substrate-uptake by whole cells. The conversion of 2-hydroxy-3-butenenitrile to 2-hydroxy-3-butenoic acid at pH 4 demonstrated the unique ability of cells of E. oligosperma R1 to hydrolyse aliphatic alpha-hydroxynitriles under acidic conditions. The organism could grow with phenylacetonitrile as sole source of carbon, energy and nitrogen. The degradation of phenylacetonitrile presumably proceeds via phenylacetic acid, 2-hydroxyphenylacetic acid, 2,5-dihydroxyphenylacetic acid (homogentisate), maleylacetoacetate and fumarylacetoacetate.
Authors:
S Rustler; A Chmura; R A Sheldon; A Stolz
Related Documents :
17722659 - Nitrogen effects on proteins, chlorophylls and fatty acids during the growth of arthros...
16902329 - Amino acid requirements of infants and children.
16259 - Nitrogen-15 nuclear magnetic resonance of aliphatic tripeptides.
11773509 - Somatotropin-induced amino acid conservation in pigs involves differential regulation o...
7305899 - The mechanism of ammonia production and the effect of mechanical work load on proteolys...
20729019 - Forensic utility of isotope ratio analysis of the explosive urea nitrate and its precur...
6883219 - Effects of inhibitors on early protein, rna, and lipid synthesis in germinating vesicul...
16659119 - Hydrogen ion entry as a controlling factor in the acid-growth response of green pea ste...
19007949 - C(35)-apocarotenoids in the yellow mutant neurospora crassa ylo.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Studies in mycology     Volume:  61     ISSN:  0166-0616     ISO Abbreviation:  Stud. Mycol.     Publication Date:  2008  
Date Detail:
Created Date:  2009-03-16     Completed Date:  2011-07-14     Revised Date:  2013-05-23    
Medline Journal Info:
Nlm Unique ID:  8411984     Medline TA:  Stud Mycol     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  165-74     Citation Subset:  -    
Affiliation:
Institut für Mikrobiologie, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Selective factors involved in oil flotation isolation of black yeasts from the environment.
Next Document:  Biodiversity of the genus Cladophialophora.