Anaerobic oxidations of cysteate: degradation via L-cysteate:2-oxoglutarate aminotransferase in Paracoccus pantotrophus.
Microbiology (Reading)
; 145 ( Pt 5): 1153-1160, 1999 May.
Article
em En
| MEDLINE
| ID: mdl-10376831
ABSTRACT
Anoxic, fresh-water enrichment cultures to oxidize different organosulfonates were set up with nitrate, ferric iron or sulfate as electron acceptors. Pure cultures were easily obtained with two naturally occurring sulfonates, cysteate (2-amino-3-sulfopropionate) and taurine (2-aminoethanesulfonate), under nitrate-reducing conditions. These two sulfonates were also oxidized during reduction of iron(III), though isolation of pure cultures was not successful. One nitrate-reducing cysteate-oxidizing bacterium, strain NKNCYSA, was studied in detail. It was identified as Paracoccus pantotrophus. Eighteen sulfonates were tested, and the organism degraded cysteate, taurine, isethionate (2-hydroxyethanesulfonate), sulfoacetate or 3-aminopropanesulfonate with concomitant reduction of nitrate, presumably to molecular nitrogen. The carbon skeleton of these substrates was converted to cell material and, presumably, CO2. The amino group was released as ammonia and the sulfono moiety was recovered as sulfate. Cell-free extracts of P. pantotrophus NKNCYSA contained constitutive L-cysteate2-oxoglutarate aminotransferase (EC 2.6.1.-) and glutamate dehydrogenase (EC 1.4.1.4). Taurinepyruvate aminotransferase, in contrast, was inducible.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Paracoccus
/
Ácido Cisteico
/
Transaminases
/
Ácidos Cetoglutáricos
Idioma:
En
Revista:
Microbiology (Reading)
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
1999
Tipo de documento:
Article