NREL Researchers Find Worth of CeIA Enzyme in Biofuel Production

In a previous study, scientists from the US National Renewable Energy Laboratory discovered an enzyme, CeIA from Caldicellulosiruptor bescii, adept at breaking down cellulose fibers regardless of its crystalline structure. According to the research, no other enzyme has shown this ability.

The original research showed that CeIA could convert biomass to sugars faster than competing commercial catalysts. This new study now focuses on how the enzyme could help remove one of the main barriers preventing cellulosic biofuels from becoming a commercial reality: the crystalline structure of cellulose.

The structure of cellulose in cell walls has been a problem for cellulases, with fungal enzymes unable to easily break down fibers with high crystalline content. CeIA however, was found to be unaffected by the level of crystalline content. It is capable of breaking down cellulose regardless of its crystallinity.

Researchers looked at how CeIA performed in breaking down and interacting with the components of cell walls in corn stover. Chemical pretreatments were used on corn stover and silky fibers called cotton linters, leaving behind various amounts of the components and varying degrees of crystallinity.

The only obstacle to CeIA was lignin, the component which gives rigidity to cell walls. With some of the chemical pretreatments, some lignin remained, stopping the enzyme.