Bacteria protein discovery could free imprisoned plant sugars

By Luke Geiver | July 03, 2012

A team of researchers from the U.S. DOE’s BioEnergy Science Center has something to say about the role of thermophilic (heat-loving) bacteria strains found in places like Russia, New Zealand or Iceland. The team, made up of 18 researchers from North Carolina State University, Oak Ridge National Laboratory and the University of Georgia, worked together to study the genomes of eight bacteria species classified under the genus Caldicellulosiruptor. Their work uncovered the possibility for the bacteria strains to be used in the ever-evolving effort to enhance the process of breaking down plant cell walls to gain access to C5 and C6 sugars used in bioenergy production methods.

Through their research and use of analysis known as proteomics, a protein analysis method that combines genome data with protein characterization, the team uncovered a previously uncharacterized group of proteins called adhesins, according to ORNL, a protein that can help the bacteria “grab onto a chunk of plant material to more efficiently break it apart.” The discovery of the adhesins helped the research team recognize why certain bacteria species in the genus family they were researching were better than others at plant deconstruction. 

“Previously, we knew these bacteria would secrete enzymes that would then freely diffuse into their environment,” according to Sara Blumer-Schuette, a researcher working on the bacteria genome project. “We assumed that the enzymes would by chance stick to either cellulose or a piece of biomass in their environment and start to degrade it.” She added that the team is now, “seeing that a lot of proteins are involved in maintaining a tight interface between the bacteria and cellulose.”

Paul Gilna, director at BESC said of the research effort, “If we can understand the processes already in place with cellulose-degrading organisms such as the Caldicellulosiruptor microbes…we can make huge leaps in learning how to harness microbes to digest plant biomass and ferment sugars into biofuels at the same time.” 

The work on the Caldicellulosiruptor genus was recently published in the Journal of Bacteriology.