Researchers tap into genetic reservoir of heat-loving bacteria

The identification of key proteins in a group of heat-loving bacteria by researchers at the Department of Energy's BioEnergy Science Center could help light a fire under next-generation biofuel production.

Scientists have long been on the hunt for cost-effective ways to break down complex plant material such as switchgrass in order to access sugars that are fermented to make biofuels. Conventional processes involve the addition of commercially produced enzymes to break down the cellulose. BESC scientists are exploring alternative options, including the use of certain bacteria that are naturally capable of deconstructing plant biomass in their environment.

To better understand the mechanisms behind this microbial ability, a team of researchers from North Carolina State University, Oak Ridge National Laboratory and the University of Georgia analysed the genomes of eight species of bacteria from the genus Caldicellulosiruptor. These bacterial species, found in globally diverse sites from New Zealand to Iceland to Russia, can degrade plant biomass at extremely high temperatures.

"Earlier, we had found that not all members of this group were able to equally degrade cellulose as others were," said NCSU's Sara Blumer-Schuette. "The main aim of this project was to figure what the true determinants were for strongly celluloytic bacteria from this genus - what made them celluloytic versus the others."

By comparing the genomes of eight related yet variable species, the research team pinpointed which genes were unique to species with the ability to break down cellulose.

The researchers, whose results are published in the Journal of Bacteriology, conducted additional analysis using proteomics to verify how these particular genes are expressed into proteins that perform cellulose degradation.