Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Jun 1997, 2159-2165, Vol 63, No. 6
M Dols, W Chraibi, M Remaud-Simeon, ND Lindley and PF Monsan
The metabolic and energetic properties of Leuconostoc mesenteroides have
been examined with the goal of better understanding the parameters which
affect dextransucrase activity and hence allowing the development of
strategies for improved dextransucrase production. Glucose and fructose
support equivalent specific growth rates (0.6 h-1) under aerobic
conditions, but glucose leads to a better biomass yield in anaerobiosis.
Both sugars are phosphorylated by specific hexokinases and catabolized
through the heterofermentative phosphoketolase pathway. During
sucrose-grown cultures, a large fraction of sucrose is converted outside
the cell by dextransucrase into dextran and fructose and does not support
growth. The other fraction enters the cell, where it is phosphorylated by
an inducible sucrose phosphorylase and converted to glucose-6-phosphate
(G-6-P) by a constitutive phosphoglucomutase and to heterofermentative
products (lactate, acetate, and ethanol). Sucrose supports a higher growth
rate (0.98 h-1) than the monosaccharides. When fructose is not consumed
simultaneously with G-1-P, the biomass yield relative to ATP is high (16.8
mol of ATP.mol of sucrose-1), and dextransucrase production is directly
proportional to growth. However, when the fructose moiety is used, a sink
of energy is observed, and dextransucrase production is no longer
correlated with growth. As a consequence, fructose catabolism must be
avoided to improve the amount of dextransucrase synthesized.
Copyright © 1997, American Society for Microbiology
Growth and energetics of Leuconostoc mesenteroides NRRL B-1299 during metabolism of various sugars and their consequences for dextransucrase production
Centre de Bioingenieric Gilbert Durand, Centre National de la Recherche Scientifique 5504, Toulouse, France.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|