2013 Annual Report
1a.Objectives (from AD-416):
Produce inexpensive biobased polymers from agricultural biomass using a simple fermentation process and test these polymers as renewable, biodegradable replacements for petroleum-based materials.
1b.Approach (from AD-416):
The mushroom Schizophyllum commune is a white rot fungus known to produce an array of enzymes needed to degrade biomass, including cellulase, xylanase and lignin-degrading enzymes. In the course of studies using this fungus to degrade agricultural biomass, we discovered that cultures also produced the biopolymer schizophyllan during degradation of corn fiber (Leathers, Nunnally, and Price, Biotechnol. Lett. 28:623-626, 2006). We developed a simple method to recover schizophyllan from residual biomass. An enriched arabinoxylan fraction was recovered as a coproduct of this process. Schizophyllan is commercially produced in Japan as a high-value pharmaceutical, specifically an immunotherapeutic agent for cancer treatment. However, the unique physical properties of the biopolymer suggest bulk applications. Claims exist for the use of schizophyllan in enhanced oil (petroleum) recovery. The high viscosity and thermal stability of solutions suggests further applications as a biobased replacement for petroleum-derived lubricants in specialty applications such as metalworking. However, to date only limited quantities of extremely expensive pharmaceutical-grade schizophyllan are available for testing. Similarly, current processes for isolation of corn fiber arabinoxylan are expensive. Corn fiber arabinoxylan also has a unique structure, and isolated corn fiber arabinoxylan gums are potentially valuable for numerous bulk industrial applications. Corn fiber gums can serve as adhesives, thickeners, stabilizers, film formers and emulsifiers. We propose to optimize and scale up production of crude schizophyllan and arabinoxylan polymers from abundant agricultural biomass, to provide material for bulk application testing. These materials will be tested as renewable, biodegradable replacements for petroleum-based materials.
The overall goal of this project is to convert agricultural materials into higher-value bioproducts, thus creating new and expanded markets for agricultural commodities and reducing our dependence on imported petroleum. Supporting objectives are to produce biobased polymers from agricultural biomass and test these polymers as renewable, biodegradable replacements for petroleum-based materials. In FY13, ARS Renewable Product Technology Research Unit scientists at the National Center for Agricultural Utilization Research, Peoria, Illinois optimized conditions for production of schizophyllan from agricultural biomass in controlled bioreactors. Bioreactor-produced polymers exhibited chemical and physical properties similar to those of commercially produced polymers.