The response of Escherichia coli central carbon metabolism to genetic and environmental manipulation has been studied by use of a recently developed methodology for metabolic flux ratio (METAFoR) analysis; this methodology can also directly reveal active metabolic pathways. Generation of fluxome data arrays by use of the METAFoR approach is based on two-dimensional (13)C-(1)H correlation nuclea...

tinuous stirred tank bioreactor, was independently invented by Jacques Monod1 and by Aaron Novick and Leo Szilard,2,3 who also coined the term chemostat. Its inventors conceived that this device provided a convenient way to study a bacterial population in the steady state, letting the experimenter adjust growth rate and external parameters, such as temperature or pH level. Novick and Szilard we...

The Microbiological Research Establishment at Porton Down—and more particularly its BiochemistrySection led by Denis Herbert—was an exciting place in which to work in the later 1960s and early 1970s. Encouraged, as we then were, to pursue fundamental microbiological research, and freedfrom the constraints of funding agencies and their “peer review” procedures, we could unashamedly engage in “bl...

We identified an open reading frame, designated phcS, downstream of the transcriptional activator gene (phcR) for the expression of multicomponent phenol hydroxylase (mPH) in Comamonas testosteroni R5. The deduced product of phcS was homologous to AphS of C. testosteroni TA441, which belongs to the GntR family of transcriptional regulators. The transformation of Pseudomonas aeruginosa PAO1c (ph...

Irrespective of the nature of the growth-limiting substance, the potassium content of Aerobacter aerogenes (growing in a chemostat at a fixed dilution rate) increased progressively from about 1.3 % to 4-2 yo of the bacterial dry weight with changes in culture NaCl concentration from o to 40 g./l. Similarly, the potassium content of glycerol-limited A. aerogenes organisms, growing in a low ionic...

Flow Microcalorimetry, E. coli K12, Aerobic Chemostat Culture The combination of a 3-liter fermentor with a flow-through calorimeter is described. Minimum time-lags are less than 10 s corresponding to maximum thermal peak disturbances of ~ 4 jiW. The set up shows an excellent long time stability. Aerobic growth of Escherichia coli K12 in batch cultures was used to test the equipment. Precision ...

The fate of glycerol trinitrate when exposed to microbial attack has been investigated. Contrary to some earlier reports, this compound was readily biodegraded by employing batch or continuous techniques under a variety of cultural conditions. Breakdown of glycerol trinitrate took place stepwise via the dinitrate and mononitrate isomers, with each succeeding step proceeding at a slower rate. Af...

The aim of the current work was to collect relevant data on the physiology of Bacillus licheniformis in chemostat cultivations. The first experiments have shown some nutrient limitation other than the carbon source in the culture medium. Besides, the growth yields observed were much smaller than expected for bacteria growing in glucose. As a consequence of the abovementioned results, the adapta...

This work reports on an instrument capable of supporting automated microscale continuous culture experiments. The instrument consists of a plastic-PDMS device capable of continuous flow without volume drift or evaporation. We apply direct computer controlled machining and chemical bonding fabrication for production of fluidic devices with a 1 mL working volume, high oxygen transfer rate (k(L)a≈...

In this paper, we tackle the problem of microalgae selection in a continuous photobioreactor where microalgae growth is limited by light. We propose a closed-loop control for selecting, for a given range of light intensity, the strain with the maximum growth rate from the microalgae population. In particular, we are interested in strains with high growth rate for high light intensity, i.e.,stra...