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Titolo:
A novel Pseudomonas putida strain with high levels of hydantoin-convertingactivity, producing L-amino acids
Autore:
Buchanan, K; Burton, SG; Dorrington, RA; Matcher, GF; Skepu, Z;
Indirizzi:
Rhodes Univ, Golds Fields Biotechnol Ctr, Dept Biochem & Microbiol, ZA-6140 Grahamstown, South Africa Rhodes Univ Grahamstown South Africa ZA-6140 0 Grahamstown, South Africa
Titolo Testata:
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
fascicolo: 4-6, volume: 11, anno: 2001,
pagine: 397 - 406
SICI:
1381-1177(20010122)11:4-6<397:ANPPSW>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
D-P-HYDROXYPHENYLGLYCINE; 5-SUBSTITUTED HYDANTOINS; DL-5-SUBSTITUTED HYDANTOINS; MICROBIAL CONVERSION; ENZYMATIC PRODUCTION; ESCHERICHIA-COLI; RESTING CELLS; MICROORGANISMS; PURIFICATION; MUTANT;
Keywords:
Pseudomonas putida; L-amino acids; hydantoinase;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Burton, SG Rhodes Univ, Golds Fields Biotechnol Ctr, Dept Biochem & Microbiol, POB 94, ZA-6140 Grahamstown, South Africa Rhodes Univ POB 94 Grahamstown South Africa ZA-6140 uth Africa
Citazione:
K. Buchanan et al., "A novel Pseudomonas putida strain with high levels of hydantoin-convertingactivity, producing L-amino acids", J MOL CAT B, 11(4-6), 2001, pp. 397-406

Abstract

Optically pure chiral amino acids and their derivatives can be efficientlysynthesised by the biocatalytic conversion of 5-substituted hydantoins in reactions catalysed by stereo-selective microbial enzymes: initially a hydantoinase catalyses the cleavage of the hydantoin producing an N-carbamyl amino acid. In certain bacteria where an N-carbamyl amino acid amidohydrolase(NCAAH) is present, the N-carbamyl amino acid intermediate is further converted to amino acid, ammonia and CO,. In this study we report on a novel Pseudomonas putida strain which exhibits high levels of hydantoin-converting activity, yielding L-amino acid products including alanine, valine, and norleucine, with bioconversion yields between 60% and 100%. The preferred substrates are generally aliphatic, but not necessarily short chain, 5-alkylhydantoins. In characterizing the enzymes from this microorganism, we have found that the NCAAH has L-selectivity, while the hydantoinase is non-stereoselective. In addition, resting cell reactions under varying conditions showed that the hydantoinase is highly active, and is not subject to substrate inhibition, or product inhibition by ammonia. The rate-limiting reaction appears to be the NCAAH-catalysed conversion of the intermediate. Metal-dependence studies suggest that the hydantoinase is dependent on the presence of magnesium and cobalt ions, and is strongly inhibited by the presence of copper ions. The relative paucity of L-selective hydantoin-hydrolysing enzyme systems, together with the high level of hydantoinase activity and the unusual substrate selectivity of this P. putida isolate, suggest that is has significant potential in industrial applications. (C) 2001 Elsevier Science B. V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/04/20 alle ore 04:10:59