Nonlinear dependency of intracellular fluxes on growth rate in miniaturized continuous cultures of Escherichia coli.

ABSTRACT: A novel mini-scale chemostat system was developed for the physiological characterization of 10-ml cultures. The parallel operation of eight such mini-scale chemostats was exploited for systematic 13C analysis of intracellular fluxes over a broad range of growth rates in glucose-limited Escherichia coli. As expected, physiological variables changed monotonously with the dilution rate, allowing for the assessment of maintenance metabolism. Despite the linear dependence of total cellular carbon influx on dilution rate, the distribution of almost all major fluxes varied nonlinearly with dilution rate. Most prominent were the distinct maximum of glyoxylate shunt activity and the concomitant minimum of tricarboxylic acid cycle activity at low to intermediate dilution rates of 0.05 to 0.2 h(-1).

SUBMITTER: Nanchen A 

PROVIDER: S-EPMC1392909 | biostudies-literature | 2006 Feb

REPOSITORIES: biostudies-literature