Overexpression of the rnf operon of Rhodobacter sphaeroides to increase hydrogen production

Abstract

Hydrogen has the potential to be a renewable fuel when produced by photosynthetic bacteria. Rhodobacter sphaeroides can produce hydrogen via the nitrogenase enzyme. In this research, several methods are used to attempt to create R. sphaeroides strains that overexpress the rnf operon. This operon codes for a protein complex that is proposed to have a role in providing nitrogenase with electrons to produce hydrogen, and its overexpression is expected to increase hydrogen yield. However, no effect on hydrogen production is observed in the overexpression strains. Future research will assay for transcripts of the rnf operon and for the Rnf complex in the experimental strains compared to their controls to determine if our strains do in fact produce higher amounts of the Rnfcomplex. If these strains are overexpressing the Rnfcomplex, then this may indicate that the Rnf complex functions somewhat differently in R. sphaeroides than has previously been suggested.