Efficient method for cellulosic conversion to glucose discovered
A team of researchers have made they are calling a "game-changing" breakthrough with an enzymatic mechanism that could revolutionise biorefining and biofuel production. The team examined how lytic polysaccharide monooxygenases (LPMOs) work at a molecular level and discovered that, to convert cellulose into fermentable sugar (glucose) – a crucial step in the biofuel process, LPMOs require hydrogen peroxide and not oxygen, which is more expensive. Using hydrogen peroxide, the team also achieved much higher conversion rates and glucose yields. Collaborative work with industrial partners has already begun. The research was undertaken at the Norwegian University of Life Sciences.
French and Norwegian scientists have discovered a ground-breaking enzymatic mechanism that could revolutionise biorefining and biofuel production.

The research focuses on enzymes known as Lytic Polysaccharide Monooxygenases (LPMOs), which in recent years have drastically improved the conversion of cellulose into fermentable sugar (glucose), a pivotal step in the creation of second generation biofuels.

Despite their common use in the commercial production of bioethanol, much ambiguity remains over how LPMOs work at a molecular level. There are also persistent challenges connected to their industrial application, the enzymes unstable under process conditions and their use requiring the costly addition of oxygen.

Bastien Bissaro, a guest researcher at NMBU (The Norwegian University of Life Sciences) from INRA, France, and an NMBU team led by Vincent Eijsink have now discovered that the mechanism by which LPMOs break down cellulose is different to previously thought. Most notably, they’ve determined that LPMOs don’t actually need oxygen to function, but hydrogen peroxide, a relatively cheap liquid chemical.

Huge significance

Bissaro and Eijsink’s discovery is a game-changer in more ways than one. Scientifically, it contradicts many of the prevailing ideas of biochemistry. From an industry point of view, it shows that the way LPMOs are harnessed in biorefining needs to be reconsidered.

Applying their findings, Bissaro and colleagues show that by controlling the supply of hydrogen peroxide, it’s possible to achieve stable enzymatic cellulose conversion processes, much higher conversion rates than previously thought possible and higher glucose yields.

A statement from NMBU makes the case that the findings, published in the journal Nature Chemical Biology, are of great commercial interest. Collaborative work with industrial partners is now underway.

Bissaro and colleagues’ findings could have ramifications beyond biomass conversion. LPMOs are abundant in nature, and are known, like hydrogen peroxide, to play a role in bacterial infections.