Project Title:  Identifying novel lignin and lignocellulose degrading enzymes from natural decomposer communities.

Principal Investigators and affiliations:

• PI: Alison Buchan (University of Tennessee, Department of Microbiology)
• Co-PI: John Sanseverino (University of Tennessee, Center for Environmental Biotechnology
• Co-PI: Todd Reynolds (University of Tennessee, Department of Microbiology)

Start Date: 9/1/2007      End Date: 8/31/2008

Project Abstract:

The lignin component of woody plant material imparts a major obstacle to biological cellulosic ethanol production by (1) forming a structurally complex molecular structure with fermentable sugars and (2) resisting degradation. Current conversion technologies employ pre-treatment strategies to liberate metabolic precursors to ethanol production, however, these practices are not ideal from the standpoint of cost, efficiency and generation of toxic by-products that inhibit downstream biological conversion reactions. This proposal seeks exploratory funding to improve pre-treatment technologies by identifying and exploiting enzymes from naturally occurring microbes that form the basis of an extremely active decomposer community in coastal salt marshes. In these highly productive ecosystems, dominated by the smooth cordgrass (Spartina alterniflora), plant material is efficiently degraded by indigenous microbial assemblages. We propose these are excellent model populations for exploring and identifying novel mechanisms for degrading lignin and liberating readily metabolizable plant constituents from the Lignocellulose matrix of switchgrass that can then be converted to biofuels. From the natural salt marsh community, we propose to

• Establish microbial consortia capable of degrading lignin and lignocellulosic components of switchgrass

• Determine rates of switchgrass lignin and lignocellulose degradation

• Identify and isolate lignolytic strains and lignin and lignocellulose degrading enzymes

As part of the long-term objectives of our research program, this exploratory research will provide the foundation for a metagenomic analysis of these active microbial populations that will allow us to pursue engineering of enzymes to enhance their activity.

Reports and Publications (pdf):

Quarter 1 - 2008
Quarter 2 - 2008
Quarters 3-4 - 2008
Quarter 1 - 2009
Project Final Report