A curious crustacean could hold secret to making renewable energy from wood

Scientists studying the digestive system of a curious wood-eating crustacean have discovered it may hold the key to sustainably converting wood into biofuel.

Gribble on a piece of wood. Credit: Claire Steele-King and Katrin Besser, University of York
Gribble on a piece of wood. Credit: Claire Steele-King and Katrin Besser, University of York

Studying the gribble, a tiny marine organism that eats wood has revealed a surprising discovery that may be an important step in the quest for renewable energy.

Until now, scientists wondered that how gribble break through lignin – the highly resistant coating that wraps around the sugar polymers that comprise wood. In the search for the answer, scientists at the University of York studied the hind gut of gribble.

The found that the Hemocyanins play a vital role in the ability to extract sugar from the wood. Through this discovery, scientists could identify cheaper and more sustainable tools for converting wood into low carbon fuel.

Hemocyanins proteins transfer oxygen in invertebrates in a similar way to hemoglobin in animals. While hemoglobin binds oxygen through its association with iron atoms, giving blood its red color; hemocyanins do this with copper atoms producing a blue color.

Oxygen is a highly reactive chemical, and gribble has harnessed the oxidative capabilities of hemocyanins to attack the lignin bonds that hold the wood together.

Professor Simon McQueen-Mason, from the Department of Biology at the University of York, who led the research team, said: “Gribble is the only animal known to have a sterile digestive system. This makes their method for wood digestion easier to study than that of other wood-consuming creatures such as termites, which rely on thousands of gut microbes to do the digestion for them.”

“We have found that Gribble chews wood into very small pieces before using hemocyanins to disrupt the structure of lignin. GH7 enzymes, the same group of enzymes used by fungi to decompose wood, are then able to break through and release sugars.”

With tension building for global action to be made on environmental change, numerous nations are quickly attempting to de-carbonize by changing to sustainable power sources, for example, biofuels.

Woody plant biomass is the most bounteous sustainable carbon resource on the planet, and, not at all like utilizing food crops to make biofuels, its utilization doesn’t come with global food security.

Co-author of the paper, Professor Neil Bruce, from the Department of Biology, said: “In the long term this discovery may be useful in reducing the amount of energy required for pre-treating wood to convert it to biofuel.

“The cellulase-enhancing effect of the haemocyanin was equivalent to that of thermochemical pre-treatments used in industry to allow biomass hydrolysis, suggesting new options for bio-based fuel and chemicals production.”

Lead author of the report, Dr. Katrin Besser, added: “it is fascinating to see how nature adapts to challenges and this discovery adds to evidence that haemocyanins are incredibly versatile and multi-functional proteins.”

The study is published in the journal Nature Communications.