U.S. Department of Energy - Energy Efficiency and Renewable Energy

Bioenergy Technologies Office

Cellulose and Enzyme Model Sheds Light on New Strategy for Conversion Process

June 27, 2013

The researchers at Los Alamos National Laboratory (LANL) and the Great Lakes Bioenergy Research Center (GLBRC)—both valuable partners of the Bioenergy Technologies Office—have published an article in the Proceedings of National Academy of Sciences that highlights a new strategy to effectively convert non-edible, or cellulosic, feedstocks into biofuels.

Cellulose is a naturally-occurring, nanofiber structure within plant cell walls that keeps the cells together, comparable to a building’s foundation. To be used, it must be broken down to create sugar, which can then be converted into biofuels or bioproducts. One of the head researchers on the team, GLBRC’s Shishir Chundawat, states that, “the key to cheaper biofuel production is to unravel these tightly packed nanofibers more efficiently into soluble sugars using fewer enzymes.” Chundawat’s team found that using one method of pretreatment to convert cellulose into a unique structure known as cellulose III increased sugar yields by as much as five times. The team also found that pretreatment resulting in cellulose III also reduced in the quantity of enzymes that bind to the service.

In response to these findings, Chundawat and a team from LANL—led by Gnana Gnanakaran and Anurag Seth—developed an advanced kinetic model to determine why this reduction in enzyme binding occurs. The model determined that cellulose III has a less sticky surface, which means that a smaller quantity of enzymes get stuck to it non-productively. The model also predicted that the enhanced enzyme activity—resulting in higher sugar yields—occurs, in spite of the reduced binding, because enzymes can more easily pull apart single strands of cellulose III than traditional cellulose. This exciting news may set the stage for future enzyme creation and development that are tailored to use cellulose III, leading to greater cost efficiency.

To learn more about their research, read the full article.