In the production of ethanol from cellulosic plant biomass, pretreatment is usually done to make the cellulose molecules more accessible for degradation into glucose (by "cellulase" enzyme treatment). The glucose is then fermented to ethanol. The development of a cost effective strategy for the pretreatment of cellulosic biomass remains one of the challenges for reducing the cost of cellulose-ethanol production. It is an active area of research. Recently, scientists from the Los Alamos National Laboratory (United States) provided new insights into the understanding of the stability of the crystalline structure of cellulose, and this could help in developing new pretreatment strategies. They constructed "a statistical mechanical model of cellulose assembly at the resolution of explicit hydrogen-bond networks." The model is reported to predict the manner by which hydrogen bonds in cellulose can shift to remain stable under a wide temperature range. The scientists identified "hydrogen bonds that can be manipulated via temperature differences" and this information can be harnessed to develop ways to make the cellulose in plant biomass more susceptible to attack by enzymes. The full results are published in the April 2009 issue of the Biophysical Journal (URL above)..