Re-investigation of glucose metabolism in Fibrobacter succinogenes, using NMR spectroscopy and enzymatic assays. Evidence for pentose phosphates phosphoketolase and pyruvate formate lyase activities

被引:22
作者
Matheron, C
Delort, AM
Gaudet, G
Forano, E
机构
[1] UNIV CLERMONT FERRAND,LAB SYNTHESE & ETUD SYST INTERET BIOL,URA 485 CNRS,F-63177 CLERMONT FERRAN,FRANCE
[2] CTR RECH CLERMONT FERRAND THEIX,INRA,MICROBIOL LAB,F-63122 ST GENES CHAMPANE,FRANCE
[3] UNIV CLERMONT FERRAND,CTR SCI & TECH,F-63177 CLERMONT FERRAN,FRANCE
来源
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH | 1997年 / 1355卷 / 01期
关键词
anaerobic bacterium; rumen; glucose metabolism; phosphoketolase; pyruvate formate lyase; NMR; C-13; (Fibrobacter succinogenes);
D O I
10.1016/S0167-4889(96)00118-8
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The glucose metabolism of Fibrobacter succinogenes S85 was studied in detail; key intermediates and alternative pathways were evidenced by NMR and/or enzymatic assays. A high phosphoketolase activity was detected in four strains of Fibrobacter under strictly anaerobic conditions, with ribose-5-phosphate as substrate, no activity was evidenced with fructose-6-phosphate. This is the first report of a pentose phosphates phosphoketolase in bacteria unable to use pentoses. In contrast, the Entner-Doudoroff pathway and the oxidative branch of the pentose phosphate pathway could not be evidenced. Incubation of living cells of F. succinogenes with (Na2CO3)-C-13 confirmed the incorporation of (CO2)-C-13 in the carboxylic group of succinate. The presence of fumarase was evidenced by in vivo C-13-NMR using 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO); the enzyme showed a high reversibility under physiological conditions. The production of formate from glucose catabolism was evidenced by enzymatic assay and by NMR and a pyruvate formate lyase activity was detected using strictly anaerobic conditions.
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页码:50 / 60
页数:11
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