Investigating the Use of Ralstonia eutropha's H2-Sensing Pathway in a Heterologous Biological H2-Sensing Reporter

Abstract

Increasing interest in alternative fuels has driven increasing interest in

biologically derived hydrogen, such as that produced by phototrophic microorganisms like cyanobacteria and green microalgae. The goal of this study was to test whether the hydrogen-sensing pathway of the soil bacteria Ralstonia eutropha could drive expression of a luciferase in a hydrogen-dependent manner so as to form a heterologous biological hydrogen-sensing reporter. Plasmids containing the hox and hyp clusters of genes reported to be necessary for hydrogen sensing in R. eutropha were introduced into Escherichia coli. However, the lack of bioluminescence in response to hydrogen demonstrated that those genes were not sufficient to serve as a hydrogen-sensitive transcription regulator in E. coli. This indicates that there is some factor not currently described that is necessary for the system's proper functioning in R. eutropha. The idea of a heterologous hydrogen-sensing reporter could be revisited once the pathways have become more fully characterized.