Team:UT-Tokyo/Project/H2 E.coli/Discussion


H2 E.coli: Discussion

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Here we analyze the results and
describe future applications.

The Effects of the E363G Mutation in fhlA Gene on Hydrogen Production

Sanchez-Torres et al. obtained by random mutagenesis several mutants of the transcriptional factor gene fhlA in which hydrogen gas production is enhanced.[1] Among these mutants, the E363G mutation allowed E.coli cells to produce hydrogen six times more than the original fhlA under anaerobic conditions with 20 mM formate. Therefore, we made a BioBrick part named fhlA -E363G by introducing the same mutation into the original wild type fhlA gene which we BioBricked.

Our aim is to make E. coli cells which are capable of producing hydrogen in a glucose-rich environment.Hydrogen production was elevated in the fhlA overexpression cells compared to the wild type. In an attempt to further increase hydrogen production, we compared the hydrogen production of two E. coli strains which over-expresses wild-type fhlA and fhlA -E363G in a glucose-rich environment. As a result, the fhlA -E363G expressing strain generated less hydrogen gas than the wild type fhlA expressing strain. It is considered that under glucose-rich conditions the E363G mutation in fhlA does not lead to an increase of hydrogen production compared to wild type fhlA.

The Effects of Formate on Hydrogen Production

We obtained the results which indicate that formate do not have significant effect on hydrogen production. The results do not support previous study, which is not conflicting to the project.

The results show that fhlA overexpression elevate hydrogen production, but there was no correlation between production efficiency and formate addition or medium and E363G mutation, which is unexpected. In order to make system more efficient, further investigation on these factors is needed.


[1]Viviana Sanchez-Torres, Toshinari Maeda, and Thomas K. Wood. Protein Engineering of the Transcriptional Activator FhlA To Enhance Hydrogen Production in Escherichia coli. APPLIED AND ENVIRONMENTAL MICROBIOLOGY 75, 5639–5646. 2009.