Central Metabolism of Escherichia Coli in the Stationery State: Flux Balance Analysis and Gene Expression Data Comparison

RESEARCH/PROJECT

Escherichia coli (E. coli) has been studied for several decades. This research project is focused on the Central Metabolism of E. coli. The main problem with the Central Metabolism is that there is a poor understanding of the metabolic changes underlying bacterial responses to growth impairment. Through the use of metabolic network modeling, we will be able to determine bacterial responses to growth impairment.

The approach to determining the objective of this project is to place the Central Metabolism into two different growth patterns. The first growth pattern will be exponential growth and the other will be stationery state. Run simulations of each pattern in single optimizations for aerobic and anaerobic glucose. Compare the simulation results with gene expression data under the two different growing patterns. The software that was used is SimPheny.

Simulations were run for both exponential growth and stationery state analysis. The final result that was found is as follows. (1) Exponential growth has a consistent growing pattern (Figure 2). (2) Stationery state has an increase of activity of glycolytic enzymes and pentose phosphate pathways enzymes (Figure 1). (3) There was also a down regulation of the TCA cycle. There are possible reasons that such disagreement when the Central Metabolism is placed in Stationery state growth is the independence of biomass.

Figure1: Stationery State

Figure 2: Exponential Growth