Limited supplies of crude oil, a desire to become less dependent on imported oil, and need to reduce greenhouse gas emissions have stimulated the search for alternative fuels from renewable resources. Cellulose and hemicellulose from lignocellulosic biomass are abundant sources of fermentable sugars, and can be obtained from corn and sorghum stover, wheat and barley straw, as well as wood chips from trees. The production of ethanol from these feedstocks requires enzymatic hydrolysis of cell wall polysaccharides, followed by microbial fermentation. While the prospects of lignocellulosic biomass as a chemical feedstock are very promising, the conversion process is not cost-effective with the current technology.

We are using an interdisciplinary approach to develop novel sources of maize germplasm in which good bio-processing characteristics and good agronomic performance are combined. The approach consists of (1) discovery of novel cell-wall related genes through an NSF-funded Plant Genome project, (2) evaluation of changes in cell wall composition on bio-processing characteristics, disease susceptibility, and biomass yield, (3) development of rapid (bio)chemical assays for yield of fermentable sugars from stover, and (4) traditional plant breeding and selection.

As a result, (1) approximately 70 novel maize cell wall mutants have been discovered trough the use of a high-throughput near infrared spectroscopy screen, (2) maize mutants that in laboratory assays result in a two-fold increase in fermentable sugars per gram stover relative to the wild-type control have been identified, (3) a rapid and inexpensive protocol to measure glucose yields with a blood glucose meter has been developed, and (4) five maize inbred lines with enhanced yields of fermentable sugars and good standability will be released in the fall of 2005.