For centuries, seafarers were plagued by wood-eating gribble that destroyed their ships, and continue today wreak damage on wooden piers and docks in coastal communities.

In March last year  research by scientists at the BBSRC Sustainable Bioenergy Centre at the Universities of York and Portsmouth discovered how the tiny marine wood-eating isopod gribble digests the apparently indigestible, having examined genes that are expressed in the guts of gribble, the researchers demonstrated that its digestive system contains enzymes which could hold the key to converting wood and straw into liquid biofuels. (Close-up of the gribble. Credit: Dr Simon Cragg and Graham Malyon -- Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, UK.)

In recent research, a team headed by Professor Simon McQueen-Mason, Professor Neil Bruce at York, and Dr Simon Cragg at Portsmouth reveal that the gribble digestive tract is dominated by enzymes that attack the polymers that make up wood. One of the most abundant is a cellulose degrading enzyme never before seen in animals.  The research is published in the latest issue of the Proceedings of the National Academy of Sciences USA (PNAS).

Unlike termites and other wood-eating animals, gribble have no helpful microbes in their digestive system. This means that they must possess all of the enzymes needed to convert wood into sugars themselves.

Professor McQueen-Mason (left) of the Centre for Novel Agricultural Products (CNAP) in the Department of Biology at York, said: "This may provide clues as to how this conversion could be performed in an industrial setting."

The York Scientist are  studying the enzymes to establish how they work, and whether they can be adapted to industrial applications. 

Professor Paul Walton and Professor Gideon Davies (right R2L) of the University’s Chemistry department, were part of an international team that has found a method to overcome the chemical intractability of cellulose, thus allowing it to be converted efficiently into bioethanol.

It represents a major breakthrough as cellulose is the world’s most abundant biopolymer.  Global generation of cellulose is equivalent in energy to 670 billion barrels of oil – 20 times the current annual global oil consumption. The discovery opens the way for the industrial production of fuels and chemicals from plentiful and renewable cellulose in waste plant matter.

The research, which is published in the Proceedings of the National Academy of Sciences (PNAS), removes the major constraint on the production of bioethanol from cellulose, the stability of which had previously thwarted previous efforts to make effective use of it for biofuels.

Researchers found a way of initiating effective oxidative degeneration of cellulose using the (right)  copper-dependent TaGH61 enzyme to overcome the chemical inertness of the material.

Professor Davies, much of whose work on plant cell-wall degradation is funded by the Biotechnology and Biological Sciences Research Council, said: “Cracking cellulose represents one of the principal industrial and biotechnological challenges of the 21st century.

"Industrial production of fuels and chemicals from this plentiful and renewable resource holds the potential to displace petroleum-based sources, thus reducing the associated economic and environmental costs of oil and gas production. Events at Fukushima and the continuing instability in major oil producing countries only highlight the need for a balanced energy portfolio.”

Professor Walton added: “This discovery opens up a major avenue in the continuing search for environmentally friendly and secure energy.  The potential of bioethanol to make a major contribution to sustainable energy really now is a reality.”

Claus Crone Fuglsang, MD at Novozymes’ research labs in Davis, California said: “Scientists have worked to figure out how to break down plant matter for the past 50-60 years. The impressive effect of GH61 was established a few years back and today it is a key feature of our Cellic CTec products.

“Fully understanding the mechanism behind GH61 is important in the context of commercial production of biofuel from plant waste and a true scientific paradigm shift. This discovery will continue to drive advances in production of other biobased chemicals and materials in the future.”```

Leila Lo Leggio, Group Leader of the Biophysical Chemistry Group at the Department of Chemistry, University of Copenhagen, said: "As a team of academic scientists, it is particularly rewarding when our basic research in the three-dimensional structure and chemistry of proteins also contributes to possible solutions for one of the major challenges our society is facing.”

Professor Paul Dupree of the University of Cambridge Bioenergy Initiative and Director of the BBSRC Sustainable Bioenergy Cell Wall Sugars programme, said "Understanding the GH61 enzyme activity is one of the most significant recent advances in the area of biomass deconstruction and release of cell wall sugars."

CULTIVATING KELP FOR BIOFUEL

An underwater “field” as big as a Norwegian county could provide 2 billion litres of kelp-based fuel a year. SINTEF is currently establishing a centre of expertise that will enable cultivating seaweed and kelp on a large scale. Chief scientist Trina Galloway (left) and State Secretary Kristine Gramstad agree that seaweed and kelp have great potential for industrial applications. Photo:(Photo: Thor Nielsen/SINTEF Media)

Kelp cultivation will mean producing bioethanol fuel in addition to biogas for heating and fuel, without the need to use food  crops as a raw material, and without having to use agricultural land or freshwater resources.

This is  among the reasons behind SINTEF’s decision to establish the Norwegian Centre for Seaweed and Kelp Technology, which was opened in Trondheim in by State Secretary Kristine Gramstad of the Ministry of Fisheries and Coastal Affairs

Many areas of application
There are even more potential uses of kelp and seaweed beyond applications as sources of energy.
As well as being an energy resource, macroalgae such as kelp and seaweed are used in food production and as agents that bind water, in biological purification systems, the reestablishment of kelp cultures in fjords that have suffered high rates of kelp mortality, as soil improvers and in the hunt for new compounds for medical and industrial applications (bioprospecting).

Exciting interface
“Macroalgae cultivation lies at an exciting interface between better resource utilisation, new marine based products and potential renewable energy production. Although the process of establishing new industry can be demanding, I believe that a maritime land such as Norway, with its major offshore and marine supply industries, solid research base and a world-beating aquaculture industry should be quite capable of achieving success in this field,” says State Secretary Gramstad.

Efficiency challenges
Today, some 15m tonnes of seaweed and kelp are cultivated all over the world, mostly in Asia, and are used in foods, animal feedstuffs, chemicals, medicines, health foods, cosmetics and fertilisers.

“The Norwegian coastline, including all its islands, is twice as long as the Equator. In other words, we possess huge areas that are suitable for cultivating seaweed and kelp. However, manpower is more expensive here than in Asia. This means that the greatest challenge lies in cultivating large volumes at sufficiently low cost, and research-based knowledge will be essentlal if we are to manage this,”says chief scientist Trina Galloway of SINTEF Fisheries and Aquaculture.

International invitations
Galloway says that SINTEF has already been cultivating kelp on a trial basis, on behalf of Norwegian industrial interests and with financial support from the the Research Council of Norway.

“We ourselves have a good deal of competence, but there are also inportant sources of knowledge elsewhere in the world. The aim of the centre is to gather all such sources of expertise into a single team, so we are inviting both Norwegian and overseas research gropups into the centre.

Could be fertilised by farmed fish
The competence centre will offer industry and the authorities its knowledge, which will cover everything from controlled production of seed plants and cultivation in the sea to harvesting and processing the raw material for a wide range of applications.

Seaweed and kelp take up nutrient salts (fertilisers) and CO2 from the sea. The plants can be cultivated in dedicated macroalgae systems, or side by side with farmed fish. The plants can thus be fertilised by the fish and thus help to cleanse the water around the sea-cages.

From harvesting to cultivation
At present, seaweed and kelp are not cultivated commercially in Norway. But we already have a major industry based on an annual harvest of around 150,000 tonnes of kelp from which alginates are extracted. These are substances that have the ability to thicken and stabilise liquids, and are therefore used in a large number of food products. Grisetang is also used to produce kelp meal, which is used as a soil improver and in animal feed and health-food products.

“Although harvesting removes less than one percent of Norway’s standing seaweed and kelp biomass, we do not recommend taking out more than this amount, as kelp forests are actually important nursery and feeding grounds for a wide range of invertebrates and fish. If we want to expand our kelp-based industry, we will have to cultivate kelp on a large scale,” says Galloway, pictured below making sure the ecosystem for small cod babies is in order with a view to cod farming. (Photo: Thor Nielsen/SINTEF Media)