Improved Conversion of Cellulose Waste to Ethanol Using a Dual Bioreactor System

Wastes from plant materials such as sawdust, wood chips, wood shavings, lawn grass, and straw are natural resources that can be transformed into useful value-added products. Wood waste and grass are major sources of cellulose, the most abundant renewable natural resource. This project will develop a defined consortium of natural microorganisms that will efficiently breakdown wood and grass waste to energy-rich soluble sugars and convert them to cleaner-burning ethanol fuel. By using whole microbial cells for the saccharification process, a vast spectrum of synergistic enzymes, required for complete degradation of lignocellulosic waste to fermentable sugars (such as glucose and xylose), will be secreted. The proposed system will be cost-efficient, simple, and highly usable by small-scale producers of fuel ethanol in local communities, including agricultural farmers. Phase I will: (1) develop a potent microbial inocula, immobilized on solid inedible plant fiber waste; (2) validate a biocatalytic hybrid column reactor system for the bioconversion of wood chips and grass waste; and (3) characterize and optimize the entire bioprocess yield by analysis of the sugar composition of the resulting plant fiber syrup. Phase II will integrate the fermentation step and will maximize bioethanol yield. Commercial Applications and other Benefits as described by the awardee: Efforts to increase energy security and industrial cost-competitiveness, boost energy efficiency, increase productivity, and prevent pollution will require that traditional chemical feed stocks (petroleum and natural gas) be supplemented with materials that are abundant in the United States. This technology will enable viable alternative feedstock pathways to be developed for large-scale commodity chemical production. The biofuel market hit $15.7 billion globally in 2005 and is projected to grow by a factor of three 2015.