ISSN:
1432-072X
Keywords:
Key wordsCorynebacterium glutamicum
;
Urea uptake
;
Secondary transport
;
Urease activity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract When Corynebacterium glutamicum is grown with a sufficient nitrogen supply, urea crosses the cytoplasmic membrane by passive diffusion. A permeability coefficient for urea diffusion of 9 × 10–7 cm s–1 was determined. Under conditions of nitrogen starvation, an energy-dependent urea uptake system was synthesized. Carrier-mediated urea transport was catalyzed by a secondary transport system linked with proton motive force. With a K m for urea of 9 μM, the affinity of this uptake system was much higher than the affinity of urease towards its substrate (K m approximately 55 mM urea). The maximum uptake velocity depended on the expression level and was relatively low [2–3.5 nmol min–1 (mg dry wt.)–1].
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002030050591
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