Mining Compost for New Microbial Enzymes to Degrade Switchgrass

The Science

Enzymatic breakdown of plant biomass is one of the most expensive steps in the production of cellulosic biofuels, mostly due to the low efficiencies of current commercially available enzymes. Deconstruction of grass feedstocks such as switchgrass and corn stover presents a particular challenge. Grass material is effectively broken down by microbial communities in compost piles, but the involved enzymes have remained largely unexplored because it is difficult to isolate the responsible organisms. Now researchers at the DOE Joint Bioenergy Institute (JBEI) have identified biomass degrading enzymes produced by compost microbes during growth on switchgrass. The team characterized genes thought to be involved in biomass breakdown and synthesized two reconstructed hemicellulose-degrading enzymes. These enzymes are promising candidates for further study and improvement by genetic engineering andsuggest potential pathways to new enzymatic treatment strategies tailored to specific biomass feedstocks.

Principal Investigator

Philip Hugenholtz
Lawrence Berkeley National Laboratory

BER Program Manager

Dawn Adin

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


Allgaier, M, A. Reddy, J.-I. Park, N. Ivanova, P. D’haeseleer, S. Lowry, R. Sapra, T.-C. Hazen, B. A. Simmons, J. S. VanderGheynst JS, and P. Hugenholtz. 2010. “Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community,” PLoS ONE 5(1): e8812.