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B6db references: 91201289

type Journal Article
authors Iwamoto, R.; Imanaga, Y.
title Direct evidence of the Entner-Doudoroff pathway operating in the metabolism of D-glucosamine in bacteria
journal J Biochem (Tokyo)
ui 91201289
year (1991)
volume 109
number 1
pages 66-9.
keywords Agrobacterium/metabolism
abstract Pseudomonas fluorescens (Migula) (IFO 14808) has both a membrane-bound PQQ-dependent D-glucose (D-Glc) dehydrogenase [EC] [which also acts on D-glucosamine (D-GlcN)] and a PLP-dependent D- glucosaminate (D-GlcNA) dehydratase [EC]. Further, these two enzymes were induced when D-GlcN was added to the culture medium. However, D-glucosamine-6-phosphate (D-GlcN-6-P) isomerase [EC], another enzyme involved in the metabolism of D-GlcN, was only present at a low level in this bacterium. The bacterium was able to grow in a minimal medium containing D-GlcN or D-GlcNA as the sole source of carbon and nitrogen. Intact cells of P. fluorescens (Migula) converted D-GlcN to D-GlcNA and then to 2-keto-3-deoxy-D-gluconate (KDGA). These results demonstrate that D-GlcN is metabolized via D- GlcNA to KDGA in P. fluorescens (Migula) (Entner-Doudoroff pathway). In contrast, Enterobacter cloacae(IFO 13535) and Agrobacterium radiobacter (IAM 1526) have significant amounts of D-GlcN-6-P isomerase with low levels of the D-Glc dehydrogenase and D-GlcNA dehydratase. Further, only the isomerase activity was induced on the addition of D-GlcN to the culture medium. These results demonstrate that there is a new route (Entner-Doudoroff pathway), i.e., in addition to the known one (Embden- Meyerhof pathway), for the metabolism of D-GlcN in bacteria and one of the two routes is predominant in the each of bacteria examined.
last changed 2004/04/16 21:17

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