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.
Researchers at the Department of Energy’s BioEnergy Science Center analyzed the genomes of eight species of bacteria from the genus Caldicellulosiruptor, which could aid in the production of next-generation biofuels.
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 analyzed 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.
The team's research uncovered a previously uncharacterized group of proteins determined to be adhesins, which help the bacteria grab onto a chunk of plant material to more efficiently break it apart. This finding further clarified why certain bacterial species in the genus are better than others at deconstructing plant material.
"Previously, we knew these bacteria would secrete enzymes that would then freely diffuse into their environment," Blumer-Schuette said. "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. Now we're seeing that a lot of proteins are involved in maintaining a tight interface between the bacterium and cellulose."
A key challenge in making the production of lignocellulosic biofuels cost-effective is improving the efficiency of access to the sugars imprisoned in a plant's cell wall.
"Yet nature, in the form of the microbes described here, has been doing this very effectively all along," said Paul Gilna, director of BESC, of which the authors are members. "If we can understand the processes already in place with cellulose-degrading organisms such as the Caldicellulosiruptor microbes described here, we can make huge leaps in learning how to harness microbes to digest plant biomass and ferment sugars into biofuels at the same time."
Coauthors of the article, which has been published online by the Journal of Bacteriology, include NCSU's Sara Blumer-Schuette, Jeffrey Zurawski, Inci Ozdemir and Robert Kelly; ORNL's Richard Giannone, Scott Hamilton-Brehm, James Elkins, Frank Larimer, Miriam Land, Loren Hauser, Robert Cottingham and Robert Hettich; and UGA's Qin Ma, Yanbin Yin, Ying Xu, Irina Kataeva, Farris Poole and Michael Adams.
BESC is one of three DOE Bioenergy Research Centers established by the DOE's Office of Science in 2007. The centers support multidisciplinary, multi-institutional research teams pursuing the fundamental scientific breakthroughs needed to make production of cellulosic biofuels, or biofuels from nonfood plant fiber, cost-effective on a national scale. The three centers are coordinated at ORNL, Lawrence Berkeley National Laboratory and the University of Wisconsin-Madison in partnership with Michigan State University.
ORNL is managed by UT-Battelle for the Department of Energy's Office of Science. DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov.
Morgan McCorkle | EurekAlert!
How cells hack their own genes
24.08.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
23.08.2017 | Life Sciences
23.08.2017 | Life Sciences
23.08.2017 | Physics and Astronomy