Chemistry Technology

Study Offers New Understanding of Top Biocatalyst for Biofuels Production

biofuel production

To create fuels from renewable sources like plants, the process of chemical cellulose must commence. A key catalyst for this process is Clostridium thermocellum – a highly prevalent microorganism that operates effectively in warm environments, even without oxygen.

Researchers at the U.S. Department of Energy BioEnergy Science Center (BESC) recently observed that C. thermocellum utilizes a previously undiscovered process to break down cellulose. This defines the microorganism’s exceptional ability to absorb biomass and illustrates nature’s diverse approaches to biomass conversion. These findings are helping develop methods to deconstruct plant matter and create biofuels and biobased chemicals.

Right now, the largest point of supply for organic matter is lignocellulosic biomass. This makes it a reliable source for generating biofuels and other chemicals. But currently, the primary roadblock in such production is the limited effectiveness of cellulose conversion, resulting in high production costs.

clostridium thermocellum
The Clostridium thermocellum is stained green and can be seen to grow on poplar tissue.
(Image Credit: Oak Ridge National Laboratory)

As of now, C. thermocellum is the most suitable organism to dissolve lignocellulosic biomass. The microbe’s cellulases are blamed for it’s high cellulose digestion capability, as they contain a free-enzyme system in addition to a tethered cellulosomal one. Scaffolding proteins arrange a number of carbohydrate active enzymes to make enormous complexes fused to the cell wall.

Recently, BESC researchers found that C. thermocellum experiences a “cell-free” system – a cellulosomal system not bound to a cell wall. They theorized that this complex acts as a “long-range” cellulosome, separating from the cell and reducing polysaccharide substrates away from it.

That means C. thermocellum uses a new division of scaffolded enzymes in addition to the mechanisms previously discovered. This astonishing discovery illustrates the organism’s remarkable abilities in biomass conversion and illustrates that nature’s methods for this process are yet to be fully utilized.

The full study was published in Science Advances journal.