New Cellulose Degrading Bacteria and Enzymes Isolated From High Temperature Compost

4 new GHF48 gene sequences were added to the known diversity of 35 genes from cultured species.

The Science

Current approaches for conversion of cellulosic biomass to biofuels rely on cocktails of cellulose degrading enzymes (i.e. cellulases) that are expensive, relatively inefficient, and not well adapted to industrial conditions. Researchers at Dartmouth College and the DOE Bioenergy Science Center (BESC) are exploring a variety of high temperature, cellulose rich environments to identify new microbes and enzyme systems with improved biomass deconstruction capabilities. They now report the discovery of genes encoding 48 new cellulase enzymes from microbes collected from a compost site with temperatures ranging from 52-72°C. Many of these genes, most of which originate from members of the bacterial class Clostridia, have substantial sequence variation from known cellulases and may have substantially different properties. In addition to providing promising new targets for developments as industrial biofuels production enzymes, these genes expand the database of cellulase gene sequences and will enable improvement of probes for discovery of additional cellulases in environmental samples.

The Impact

The exploration and understanding of cellulose fermentation capabilities in nature could inform and enable industrial processes converting cellulosic biomass to fuels and other products. Enrichment of microbial communities that can utilize cellulose is useful in this context for the identification of novel organisms, novel metabolisms, and novel functions. Of particular interest are communities that can utilize cellulose at high temperatures and under anaerobic conditions, featuring high rates of solubilization under conditions where the energy and the reducing power of substrates are conserved in potentially useful fermentation products.


The enrichment from nature of novel microbial communities with high cellulolytic activity is useful in the identification of novel organisms and novel functions that enhance the fundamental understanding of microbial cellulose degradation. In this work researchers identify predominant organisms in three cellulolytic enrichment cultures with thermophilic compost as an inoculum.

Principal Investigator

Lee R. Lynd
Oak Ridge National Laboratory

BER Program Manager

Dawn Adin

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]


Izquierdo, J. A., M. V. Sizova, & L. R. Lynd. 2010. “Diversity of Bacteria and Glycosyl Hydrolase Family 48 Genes in Cellulolytic Consortia Enriched from Thermophilic Biocompost,Applied and Environmental Microbiology 76, 3545–53. DOI:10.1128/AEM.02689-09.