Flux Balance Analysis

Our synthetic pathway produces Hydrogen. Our chassis fixes Nitrogen, which is influenced by Hydrogen availability. Therefore, we were keenly interested in finding out how our synthetic pathway would interact with the host metabolism. After some exploratory consultation, we determined Flux Balance Analysis was an effective tool for this.

Introduction

Flux Balance Analysis (FBA) can serve to explore the fluxes of a given metabolic reconstruction. In this case, we wanted to determine the level and extent of interaction of our added pathway with the core metabolism. Since our chassis, R.etli, has two "flavors" (free living organism & plant symbiont), we were curious as to weather our transgenic system would remain functional under symbiont form. Moreover, since a key aspect of the project was Nitrogen fixation, we wanted to ensure said pathway was as functional as it could be.

Furthermore, key researchers at our University warned us against the project due to the widespread presence of endogenous hydrogenases. These native enzymes play the opposite role of the activity we were interested in, they consume molecular hydrogen instead of producing it. Apparently, since Nitrogen fixation produces molecular hydrogen, some Rhizobial species developed capture hydrogenases to recycle the protons into the all-important proton gradient that feeds cellular machinery. However, our particular strain, CFN42, doesn't have any capture hydrogenase. Nonetheless, since nature developed pathways to do the exact opposite of what we're doing, we were interested in finding out any toxic or deleterious effects our system might have. Finaly, out goals can be stated as being:

1. Under symbiont form, our transgenic chassis is capable of Hydrogen production?
2. To what extent does the Hydrogen production affect core metabolism, and Nitrogen fixation?
3. Is there a toxic effect derived from Hydrogen production?

Theoretical Background

The Simulation

The Results