Molecular and genetic analysis of Desulfovibrio

Abstract

The current population explosion has resulted in an ever-increasing demand for petroleum-based fuels, consequently global fossil fuel reserves are diminishing at record pace. To provide a sustainable future for the next generation, renewable alternatives to current fuels products are required. Desulfovibrio spp. has been reported to microbially synthese hydrocarbons of similar structure to that found in petroleum-based fuel products. Exploration of the hydrocarbon synthesis pathway through transcriptomic analysis highlights the genes and proteins involved. Comparative RNA-seq analysis between two homologous strains of Desulfovibrio; Desulfovibrio desulfuricans 8326 and Desulfovibrio salexigens 2638 provided growth characterisation and the development of a reliable RNA extraction method when cultivated in Postage medium B. Bioinformatic analyses are currently pending to identify components accountable for hydrocarbon synthesis. Complementary C18 alkane and 16S genetic analysis confirmed D.desulfuricans hydrocarbon synthesis but highlighted contamination of D.salexigens cultures resulting in false-positive alkane production. Additional transformation investigations of D.desulfuricans confirmed natural resistance markers. Supplementary work to generate a highly transformable strain lacking the hsdR gene examined two methods of gene deletion; TargeTron and Cre-lox. Neither methodology provided viable transformants. Future work in developing a ‘tool box’ for genetic manipulation using a highly transformable strain of D.desulfuricans would allow control of the hydrocarbon synthetic pathway through regulation of genes discovered in the RNA-seq analysis. This new insight would improve our knowledge and enhance the future viability of renewable microbial-derived hydrocarbons as a replacement for the current non-renewable petroleum-based fuels.