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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Cell Wall Biology and Utilization Research » Research » Publications at this Location » Publication #167191

Title: WOOD ADHESIVE FORMULATIONS PREPARED FROM ALFALFA FIBER FERMENTATION RESIDUES OF RUMINOCOCCUS ALBUS AND CLOSTRIDIUM THERMOCELLUM

Author
item Weimer, Paul
item Koegel, Richard
item LORENZ, LINDA - FOREST SERVICE
item FRIHART, CHARLES - FOREST SERVICE
item KENEALY, WILLIAM - FOREST SERVICE

Submitted to: Applied Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2004
Publication Date: N/A
Citation: N/A

Interpretive Summary: In the absence of oxygen, some bacteria can convert cellulose, the main component of plant fiber, to ethanol, a liquid transportation fuel. In addition to making their own fiber degrading enzymes, some of these bacteria make a sticky slime material that allows them to attach to cellulose fibers as they decompose the fibers. We demonstrate that the fiber, with attached slime and bacterial cells, can be recovered at the end of the fermentation, and when properly dried can serve as a component of a new type of adhesive material for producing plywood. Thus, these bacteria make two valuable products (ethanol and adhesive) which have the potential to improve the overall economics of a direct fermentation process for biomass conversion.

Technical Abstract: Fermentation residues (consisting of incompletely fermented fiber, adherent bacterial cells, and a glycocalyx material that enhanced bacterial adherence) were obtained by growing the anaerobic cellulolytic bacteria Ruminococcus albus 7 or Clostridium thermocellum ATCC27405 on a fibrous fraction derived from alfalfa (Medicago sativa L.). The dried residue was able to serve as an effective co-adhesive for phenol-formaldehyde (PF) bonding of aspen veneer sheets to one another. Testing of the resulting plywood sheets revealed that the adhesive, formulated to contain 30% of its total dry weight as fermentation residue, displayed shear strength and wood failure values under both wet and dry conditions that were comparable to those of industry standards for PF that contained much smaller amounts of fillers or extenders. By contrast, PF adhesives prepared with 30% of dry weight as either unfermented alfalfa fiber or conventional fillers or extenders, rather than as fermentation residues, displayed poor performance, particularly under wet conditions.