Dissection of the Hydrogen Metabolism of the Enterobacterium Trabulsiella guamensis: Identification of a Formate-Dependent and Essential Formate Hydrogenlyase Complex Exhibiting Phylogenetic Similarity to Complex I

Biological H2 production presents an attractive alternative for fossil fuels. However, in order to compete with conventional H2 production methods, the process requires our understanding on a molecular level. FHL complexes are efficient H2 producers, and the prototype FHL-1Ec complex inE. coli is well studied. This paper presents the first biochemical characterization of an FHL-2-type complex. The data presented here will enable us to solve the long-standing mystery of the FHL-2Ec complex, allow a first biochemical characterization ofT. guamensis ’s fermentative metabolism, and establish this enterobacterium as a model organism for FHL-dependent energy conservation.