PubMed Health⌕ Search

PubMed · 7576534

Flux analysis of microbial metabolic pathways using a visual programming environment.

Abstract

This paper describes the use of a visual programming environment (LabVIEW) for the flux analysis of metabolic pathways. Representations of metabolic pathways are constructed in software from individual reaction elements (icons) which are linked together to indicate potential flux routes. Off-line bioprocess data are then used to supply the inputs and outputs to the metabolic pathway and the pathway fluxes are calculated. The metabolic system can be modelled at different levels of complexity and new pathways can be inserted into existing models. To illustrate this, flux analyses are performed on three Escherichia coli mutants with metabolic pathway deletions and insertions. The first analysis looks at organic acid production and the second at the effect of the presence in E. coli of an engineered pathway for toluene degradation.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L Regan, M Gregory. 1995-09-29. Flux analysis of microbial metabolic pathways using a visual programming environment.. https://doi.org/10.1016/0168-1656(95)00076-3

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Characterization of bioreaction processes: aerobic Escherichia coli cultures.

The simulation of a microbial transformation course is an important tool for the optimal design or characterization of industrial processes. Usually, models are developed to describe a specific part of the culture such as microbial growth and most of the time ignore the influence of physical and chemical environment on growth dynamics of the microorganism. In this work we propose a method which combines the description of the evolution of components involved in the bioprocess including biomass and the physical environment generated mainly by the bioreactor characteristics and operational conditions. Stoichiometric, kinetic, fluid dynamics and mass transfer models are linked to predict the course of the Escherichia coli culture under the influence of different experimental conditions and types of bioreactors. A set of 22 kinetic and physical parameters obtained from independent experiments and from literature are used in order to predict glucose, biomass, acetate, dissolved oxygen and CO(2) concentrations in airlift and stirred tank bioreactors.

Acetates↗

Olfactory discrimination ability for homologous series of aliphatic ketones and acetic esters.

We tested the ability of human subjects to distinguish between members of homologous series of aliphatic ketones (2-butanone to 2-decanone) and acetic esters (ethyl acetate to n-octyl acetate). In a forced-choice triangular test procedure, 20 subjects per series were repeatedly presented with all 21 binary combinations of the seven stimuli and asked to identify the bottle containing the odd stimulus. We found (a) that as a group, the subjects performed significantly above chance level in all tasks but three with the ketones, and all tasks but six with the acetic esters, and thus were clearly able to discriminate between most of the odor pairs presented; (b) marked interindividual differences in discrimination performance, ranging from subjects who were able to significantly distinguish between all 21 odor pairs of a series to subjects who failed to do so with the majority of tasks; and (c) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length for both homologous series. In line with findings of two previous studies using homologous series of aliphatic alcohols, aldehydes, and carboxylic acids, our results suggest that carbon chain length may generally be an important determinant of the interaction between stimulus molecule and receptor, and thus may generally be a molecular property affecting odor quality of aliphatic substances.

Acetates↗

Effect of selective or combined inhibition of integrins alpha(IIb)beta(3) and alpha(v)beta(3) on thrombosis and neointima after oversized porcine coronary angioplasty.

BACKGROUND: Thrombosis and neointima formation limit the efficacy of coronary angioplasty (PTCA). Clinical trials have implicated the adhesion molecules integrin alpha(IIb)beta(3) and integrin alpha(v)beta(3) in these processes. The roles of these molecules in vascular smooth muscle cell adhesion, platelet aggregation, and the thrombotic and neointimal response to oversize porcine PTCA was investigated by use of a selective alpha(IIb)beta(3) antagonist (lamifiban), a selective alpha(v)beta(3) antagonist (VO514), and a combined alpha(IIb)beta(3)/alpha(v)beta(3) antagonist (G3580). METHODS AND RESULTS: In vitro, both alpha(v)beta(3) inhibitors caused dose-dependent inhibition of porcine vascular smooth muscle cell adhesion to vitronectin but not to collagen type IV, fibronectin, or laminin, whereas selective alpha(IIb)beta(3) inhibition had no effect. Intravenous infusions of either alpha(IIb)beta(3) inhibitor in swine profoundly inhibited ex vivo platelet aggregation to ADP, whereas selective alpha(v)beta(3) inhibition had no effect. In a porcine PTCA model, intravenous infusions of the integrin antagonists were administered for 14 days after oversized balloon angioplasty injury. After PTCA, there was regional upregulation of integrin alpha(v)beta(3) in the developing neointima, as assessed by immunohistochemistry. Six hours after PTCA, obstruction of lumen by thrombus was reduced significantly by alpha(IIb)beta(3) inhibition compared with either control or alpha(v)beta(3) inhibition (mean control, 18.7%; VO514, 18.5%; lamifiban, 6.4%; G3580, 7.9%). Twenty-eight days after PTCA, there was a significant reduction of neointima with inhibitors of either integrin (mean intima/media ratio: control, 3.08; VO514, 1.33; lamifiban, 0.97; G3580, 1.32). CONCLUSIONS: We conclude that both integrin alpha(IIb)beta(3) and integrin alpha(v)beta(3) participate in neointima development after experimental angioplasty.

Acetates↗