Hot springs microbe may hold key to biofuels production

Researchers discovered a microbe at the Great Boiling Spring in Nevada which may have implications for the production of biofuels.
University of Maryland/Courtesy
Researchers discovered a microbe at the Great Boiling Spring in Nevada which may have implications for the production of biofuels.

A team of researchers including scientists at UC Berkeley recently discovered a new microbe capable of digesting cellulose at record-breaking temperatures,  a discovery which could have impacts on the production of biofuels.

The research — which was published online July 5 in the journal Nature Communications — was conducted by a team led by campus professor of chemical engineering Douglas Clark and Frank Robb, a professor at the University of Maryland School of Medicine.

According to the study, the team traveled to the Great Boiling Spring in northern Nevada — where the water temperature was known to be a consistent 95 degrees Celsius — to investigate the possibility of finding a microbe that could withstand high temperature conditions while digesting cellulose, a major component of plants.

The goal of the research was to “find a microorganisms that could take apart or deconstruct cellulose at temperatures approaching 100 degrees centigrade,” Robb said.

An enzyme the microbe produces called cellulase digests cellulose, which is responsible for maintaining a plant’s shape and structure — qualities which make it hard to digest.

According to the study, the cellulase the microbe produces is capable of digesting cellulose at very high temperatures — optimally at 109 degrees Celsius — making it completely unique.

“People are excited about (the enzyme) because it is so relatively unusual,” Robb said.

Robb added that despite the fact that this particular enzyme cannot yet be produced in large quantities, it is still valuable because it has many properties that can be salvaged and reused.

“Ultimately, this industry has to have a lot of these enzymes that are sufficiently stable that you could actually reuse them and not discard them after use,” he said. “The important properties of these enzymes that are finally used for breaking down cellulose (is) that they should be very, very stable.”

According to Jamie Cate, a campus associate professor of chemistry, biochemistry and molecular biology, this enzyme could possibly impact the development of biofuels by addressing the issue of difficulty in extracting sugar from plant cell walls.

Cate said that this enzyme might help improve the process of taking the insoluble parts of the plant cell wall and breaking them up to make soluble sugars that could be converted into biofuels.

He added that despite the enzyme’s discovery, large-scale production of biofuels may still take five to 10 years because the enzyme “is only piece of the puzzle.”

According to Robb, in addition to use in biofuels, the enzyme has potential in the field of synthetic biology. The enzyme could provide a means for building cellulase enzymes with different properties, he said.

“(The enzyme) could provide a toolkit for building cellulase enzymes that have different and enhanced properties,” he said. “It could be part of a project in synthetic biology, which is rebuilding biological molecules to achieve new properties.”