Assays

In order to construct an in vivo-like buffer for S. pyogenes, the intracellular concentrations of Fe, K, Mg, Mn Na, P and S elements were determined via ICP-AES (inductively coupled plasma atomic emissionspectroscopy) method at the Institute of Land Use, University of Rostock. The samples for the analysis were obtained from a steady state culture grown on CDM-LAB with glucose.

We developed a new metabolomics protocol, which involved a comparison of different harvesting techniques, quenching solutions and extraction methods. Cell leakage and metabolite recovery was determined by ATP measurements

This assay is designed to obtain the in vitro kinetic data of T. brucei recombinant trypanothione synthetase. The enzyme catalyzes the ATP-dependent ligation of spermidine (Spd) and GSH to generate glutathionylspermidine (Gsp) and also of Gsp and GSH to finally produce trypanothione (T(SH)2). The data was obtained in an spectrophotometric assay that links ADP production with NADH consumption through the piruvte kinase and lactate dehydrogenase.

This assay is for method development to quantify intra- and extra-cellular metabolites on T. brucei 427 bloodstream form using isotope ratio based MS technique with 13C-labelled E. coli extract

Intracellular metabolites in T. brucei at different stage of cell growth have been quantified absolutely by isotope ratio based MS technique using uniformly 13C-labelled E. coli extract. This is the case study for method development of absolute quantification for metabolic flux analysis.

Metabolite profiling on T. brucei exposed to methylene blue has been carried out using LC-MS to investigate metabolic changes caused by oxidative stress

26 intracellular metabolites (amino acids, polyamines, TCA intermediates) in T. brucei exposed to methylene blue have been absolutely quantified using isotope ratio based MS technique.

26 intracellular metabolites (amino acids, polyamines, TCA intermediates) in T. brucei under pH stress (pH8.7) have been absolutely quantified using isotope ratio based MS technique.

Extracellular metabolites in T. brucei at different stage of cell growth have been quantified absolutely by isotope ratio based MS technique using uniformly 13C-labelled E. coli extract. This is the case study for method development of absolute quantification for metabolic flux analysis.

Glucose transporter mutants were analyzed under aerobic and aerobic conditions in batch cultures with glucose as substrate. Acetate formation rates and glucose consumption rates were measured, as well as extracellular cAMP concentrations.

Mutant strains which lack one or more of the glucose transport systems were analyzed in aerobic chemostat cultures and compared to batch cultures.

MG1655 and mutant strains with defects in glucose transport systems were analyzed in aerobic and anaerobic batch cultures.

ArcA phosphorylation in chemostat cultures grown at different aerobiosis levels was quantitated by Phos-tag SDS-PAGE gel analysis and subsequent immunodetection of ArcA.

Concentration of glycolytic intermediates over time

Kinetic characterisation of phosphoglycerate kinase

S. pyogenes M49 (591), E. faecalis V583, and L. lacis NZ9000 and their isogenic ldh deletion mutants were grown glucose free CDM-LAB medium in BIOLOG phenotype microarray plates PM01 and PM02. With this assay the abilitiy of the strains to grow on 190 different carbon sources was determined in 96 well format.

L. lactis was grown in LAB medium or rich THY medium, strongly concentrated and glucose-pulsed in a MES buffer. Intracellular metabolite concentration is followed in time.

Measurements on Km, Vmax and allosteric activation or inhibition of the heterologously expressed (E. coli) and purifiied main L-lactate dehydrogenase

Measurements on Km, Vmax and allosteric activation or inhibition of the main L-lactate dehydrogenase

Global sensitivity analysis of a kinetic model to determine the sensitivities for each parameter, over a wide parameter range. We used the elementary effects method.

Lumped kinetic model of L. lactis glycolysis, formulated with ordinary differential equations. Simulations are in line with experimental data

This experiment uses a low-copy plasmid based system (MG1655 Δlac FF(-41.5)/RW50) for measuring FNR activity. Initial acetate calibration of the chemostat with the MG1655 Δlac strain was carried out, with β-galactosidase activity from the FF(-41.5)/RW50 reporter plasmid measured at 100%, 80%, 50%, 20% and 0% aerobiosis levels. Finally, the aerobiosis levels were re-determined by calculating the actual acetate flux in the sampled chemostat runs.

Note: the strain used (MG1655 Δlac) is not the same ...

The task of this assay is to determine the impact of oxygen availability on the concentrations of metabolites from different central metabolic pathways. The focus lies on metabolites connected to glycolysis, tri-carbon-acid-cycle and energy metabolism. All strains have been cultured and analysed according to the SOPs listed below

Theoretical analysis of hypothetical sigma factor competition. Based on the model 'transcription factor competition' possible dynamics of sigma factor competition are simulated and analysed using Lineweaver-Burk representations.