In 1990 a University of Florida microbiologist, Lonnie Ingram, transferred genes responsible for ethanol fermentation to E. coli from another bacterium. Many of the descriptions and examples in the patent involved hemicellulosic sugars, which make up a large fraction of the sugars available in cellulosic biomass such as corn stalks and wood chips. The patent thus described a way to make cellulosic-ethanol production practical. It has been cited 23 times, including four in 2010, suggesting that it's one of the more important patents in the field. Above is IPVision's interactive analysis
of Ingram's patent and its impact.