Investigations

Aim. To provide critical quantitative parameter information and to model redox balance by determining the cellular concentration of all enzymes involved in the trypanothione-dependent hydroperoxide detoxification system of trypanosomes and by performing the kinetic characterization of the involved enzymes under pseudo-physiological conditions.

Cultures grown under standard SUMO conditions were analyzed with respect to heterogeneity in gene expression. To this end GFP reporter strains were constructed and GFP expression at single cell level was monitored by flow cytometry.

The electron transport chain of E. coli is branched. Different NAD Dehydrogenases and terminal oxidases are known to be expressed at different oxygen availabilities. By deleting multiple genes mutant strains were constructed that posses a linear electron transport chain. These mutants were investigated in continous bioreactor experiments with limiting glucose and varying oxygen supply.

An investigation in the central carbon metabolism of S. solfataricus with a focus on the unique temperature adaptations and regulation; using a combined modelling and experimental approach.

Investigating oscillations at the level of yeast populations and individual cells

A further investigation of the variation of FNR number in E.coli Cyo/Cyd mutants is carrying out at different oxygen supply levels. The agent-based FNR and ArcBA model is going to be used for this prediction. The number of Cyo or Cyd and other unrelated agents would be set as ‘0’ at the initial XML file with which the model starts. According to the restrictions of supercomputer ‘Iceberg’ (serviced provided by the University of Sheffield), certain parameters, such as memory per node, would be ...

In Escherichia coli several systems are known to transport glucose into the cytoplasm. A series of mutant strains were constructed, which lack one or more of these uptake systems. These were analyzed in aerobic and anaerobic batch cultures, as well as glucose limited continuous cultivations.

Transcriptional and physiological responses of anaerobic steady state cultures to pulses of electron acceptors, specifically nitrate, trimethylamine-N-oxide (TMAO)

The aim of the study is to assess the global function of RNase Y in RNA processing and degradation in Bacillus subtilis. To this end we constructed a strain allowing controlled depletion of RNase Y and used microarrays to analyze the transcriptome in response to the expression level of RNase Y.

The aims of this investigation is to quantify metabolites associated with pathways involved in stress responses for parameterising models of oxidative stress metabolism; the measurement of metabolic fluxes of metabolites of interest with intracellular concentrations

Automated model building using Taverna workflows from KEGG-Database

Multiply perturbations of trypanosome redox metabolism, closing the feedback loop between experimentation and in silioc modelling, allowing model refinement or, where there are unexpected outcomes, re-evaluation. Providing a dynamic picture of cell physiology by examining programmed metabolic changes during the developmental life-cycle of these parasites as they adapt to very different external milieus, including distinct levels of oxidative stress and unique adaptations of their redox balance ...

methods developed during COSMIC

Despite a long history in using C. acetobutylicum, little is known about the regulation of the metabolic shift, the characteristics of key-regulatory elements as well as bottlenecks of the metabolism. Goal of the collaborative project ´COSMIC-2` (Clostridium acetobutylicum Systems Microbiology 2; part of ‘SysMO’) is to increase the knowledge of this clostridial metabolism and its regulatory patterns. The focus will be on the key regulatory and metabolic events that occur during the shift from the ...

A key insight, emerging from discussions and data between the projects PIs, was the importance of switching rates in bistable systems. While the existence of multiple steady states in bistable systems can be described by universal models (that do not differ between different systems), switching rates from one stable state to another depend on the molecular details of the system under consideration.

Aim. Constructing a predictive, dynamic model of the redox metabolism of trypanosomes. Aided by this model we will quantify the impact of gene-expression and metabolic regulation on redox metabolism. The model will be constructed in an iterative cycle of experimentation – modelling – analysis – experimentation, such that it can be extended and refined based on new experimental insights.

The objective of this project is an integrated understanding the metabolic, proteomic and genetic network that controls the transition from growth to glucose starvation. This transition is a fundamental ecophysiological response that serves as a scientific model for environmental signal integration and is pivotal for industrial fermentations of Bacillus that occur predominantly under nutrient starvation.

Keywords: Glucose starvation, Transcriptomics, Proteomics, Metabolomics,Bacillus subtilis,

Clostridia are very ancient bacteria which evolved before the earth had an oxygen atmosphere. To them the air we breathe is a poison. To survive they produce a spore resting stage, resistant to physical and chemical agents.

Some species cause devastating diseases, such as the superbug Clostridium difficile. On the other hand, most are totally harmless, and make a wide range of chemicals useful to man. The best example is Clostridium acetobutylicum which makes butanol. Butanol is an alcohol, which ...

Investigation of how the ENA1 gene is transcriptionally regulated.

Changing the oxygen availability leads to an adaptation of Escherichia coli at different biological levels. After pertubation of oxygen in chemostat experiments the microorganism(s) will come back to another steady state. This investigation deals with these stationary responses of Escherichia coli within the aerobiosis scale. The change for different biological variables, in different areas of the organism like the electron transport chain, the TCA cycle or globally is investigated by wildtype ...

Changing the oxygen availability leads to an adaptation of Escherichia coli at different biological levels. After pertubation of oxygen in chemostat experiments there are very quick responses. This investigation deals with this dynamical behaviour (transitions) of Escherichia coli within the aerobiosis scale. The change for different biological variables, in different areas of the organism like the electron transport chain, the TCA cycle or globally is investigated by wildtype and mutants experiments ...

The Sulfolobus systems biology (‘‘SulfoSYS’’)-project represented the first (hyper-)thermophilic Systems Biology project, funded within the European trans-national research initiative ‘‘Systems Biology of Microorganisms’’. Within the SulfoSYS-project, focus lies on studying the effect of temperature variation on the central carbohydrate metabolism (CCM) of S. solfataricus that is characterized by the branched Entner–Doudoroff (ED)-like pathway for sugar (glucose, galactose) degradation and the ...

Experimental approaches to evaluate cellular response to Potassium limitation. For this purpose, a series of isogenic strains derived from BY4741 and lacking one (TRK1 or TRK2) or both TRK genes encoding specific potassium uptake systems was constructed using the homologous recombination and Cre-lox system.

Challenge: Comparative analyses, as demonstrated by comparative genomics and bioinformatics, are extremely powerful for (i) transfer of information from (experimentally) well-studied organisms to the other organisms, and (ii) when coupled to functional and phenotypic information, insight in the relative importance of components to the observed differences and simalities. The central principle of this proposal is that important aspects of the functional differences between organisms derive not ...

Investigation of dynamics of the central metabolism (glycolysis, PPP, anaplerotic reactions, purines) of yeast Saccharomyces cerevisiae in anaerobic conditions

Steady state metabolic fluxes and metabolite concentrations of yeast Saccharomyces cerevisiae in anaerobic chemostat at D=0.1 h-1

Bacillus subtilis was subjected to various stress conditions like high temperature(57°C), low temperature(16°C), high osmalarity(1.2M NaCl). The above mentioned stress conditions are again split into two different types as 'continuous stress condition' and 'sudden shock'. All the conditions were then done in biological triplicates. Transcriptome for these samples was then analysed with Nimblegen Tiling array.

Cellular parameters of strains lacking both TRK1 and TRK2 genes.