Thermophilic bacteria prove to be efficient biocatalysts for biomass solubilization.
A comprehensive comparison of lignocellulosic solubilization by various thermophilic bacteria to standard enzyme treatment found microbial solubilization of cellulosic biomass to be more effective, and enhanced by mechanical disruption.
Using thermophilic bacteria instead of expensive yeast enzymes to decompose biomass into its sugars for fermentation into biofuels will greatly reduce costs and potentially simplify the process.
Feedstock recalcitrance is the greatest barrier to cost-effective production of cellulosic biofuels. To overcome this recalcitrance, existing commercial cellulosic ethanol facilities employ thermochemical pretreatment with subsequent addition of fungal cellulase. However, processing cellulosic biomass without thermochemical pretreatment may be possible using thermophilic, cellulolytic bacteria. Researchers at the Department of Energy’s (DOE) BioEnergy Science Center (BESC) examined the ability of various thermophilic bacteria to solubilize autoclaved, but otherwise unpretreated cellulosic biomass. Carbohydrate solubilization of mid-season harvested switchgrass after 5 days ranged from 24 percent to 65 percent, with Clostridium thermocellum showing the best results among the four thermophiles tested. This finding was as much as fivefold better than with the standard method using a fungal cellulase cocktail and yeast fermentation. Other findings showed that there was equal fractional solubilization of glucan and xylan, and, importantly, that there was no biological solubilization of the noncarbohydrate fraction of biomass. A fivefold improvement over standard treatment was observed when using the most effective biocatalyst. Using thermophilic bacteria in biomass-solubilizing systems may enable a reduction in the amount of nonbiological processing required and, in particular, substitution of cotreatment for pretreatment.
Contacts (BER PM)
N. Kent Peters, SC-23.2, firstname.lastname@example.org, 301-903-5549
Professor, Thayer School of Engineering, Dartmouth College
This research was sponsored by BESC, a DOE Bioenergy Research Center supported by the Office of Biological and Environmental Research within DOE's Office of Science. TYN was supported by the National Science Foundation. The generation of the CCRC series of plant cell wall glycan-directed monoclonal antibodies used was supported by NSF's Plant Genome Program.
Paye, J. M. D., et al. 2016. “Biological Lignocellulose Solubilization: Comparative Evaluation of Biocatalysts and Enhancement via Cotreatment,” Biotechnology for Biofuels 9(8), DOI 10.1186/s13068-015-0412-y. (Reference link)
SC-23.2 Biological Systems Science Division, BER
BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER
Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]
Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]
Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]
Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]
Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]
List all highlights (possible long download time)