̽��ֱ�� of Cambridge - biofuel

‘Glue’ that makes plant cell walls strong could hold the key to wooden skyscrapers

cjb250 — Wed, 21 Dec 2016 09:05:15 +0000

̽��ֱ��two most common large molecules – or ‘polymers’ – found on Earth are cellulose and xylan, both of which are found in the cell walls of materials such as wood and straw. They play a key role in determining the strength of materials and how easily they can be digested.

For some time, scientists have known that these two polymers must somehow stick together to allow the formation of strong plant walls, but how this occurs has, until now, remained a mystery: xylan is a long, winding polymer with so-called ‘decorations’ of other sugars and molecules attached, so how could this adhere to the thick, rod-like cellulose molecules?

“We knew the answer must be elegant and simple,” explains Professor Paul Dupree from the Department of Biochemistry at the ̽��ֱ�� of Cambridge, who led the research. “And in fact, it was. What we found was that cellulose induces xylan to untwist itself and straighten out, allowing it to attach itself to the cellulose molecule. It then acts as a kind of ‘glue’ that can protect cellulose or bind the molecules together, making very strong structures.”

̽��ֱ��finding was made possible due to an unexpected discovery several years ago in Arabidopsis, a small flowering plant related to cabbage and mustard. Professor Dupree and colleagues showed that the decorations on xylan can only occur on alternate sugar molecules within the polymer – in effect meaning that the decorations only appear on one side of xylan. This led the team of researchers to survey other plants in the Cambridge ̽��ֱ�� Botanic Garden and discover that the phenomenon appears to occur in all plants, meaning it must have evolved in ancient times, and must be important.

To explore this in more detail, they turned to an imaging technique known as solid state nuclear magnetic resonance (ssNMR), which is based on the same physics as hospital MRI scanners, but can reveal structure at the nanoscale. However, while ssNMR can image carbon, it requires a particular heavy isotope of carbon, carbon-13. This meant that the team had to grow their plants in an atmosphere enriched with a special form of carbon dioxide – carbon-13 dioxide.

Professor Ray Dupree – Paul Dupree’s father, and a co-author on the paper – supervised the work at the ̽��ֱ�� of Warwick’s ssNMR laboratory. “By studying these molecules, which are over 10,000 times narrower than the width of a human hair, we could see for the first time how cellulose and xylan slot together and why this makes for such strong cell walls.”

Understanding how cellulose and xylan fit together could have a dramatic effect on industries as diverse as biofuels, paper production and agriculture, according to Paul Dupree.

“One of the biggest barriers to ‘digesting’ plants – whether that’s for use as biofuels or as animal feed, for example – has been breaking down the tough cellular walls,” he says. “Take paper production – enormous amounts of energy are required for this process. A better understanding of the relationship between cellulose and xylan could help us vastly reduce the amount of energy required for such processes.”

But just as this could improve how easily materials can be broken down, the discovery may also help them create stronger materials, he says. There are already plans to build houses in the UK more sustainably using wood, and Paul Dupree is involved in the Centre for Natural Material Innovation at the ̽��ֱ�� of Cambridge, which is looking at whether buildings as tall as skyscrapers could be built using modified wood.

̽��ֱ��research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

Reference
Simmons, TJ et al. Folding of xylan onto cellulose fibrils in plant cell walls revealed by solid-state NMR. Nature Communications; Date; DOI: 10.1038/ncomms13902

Molecules 10,000 times narrower than the width of a human hair could hold the key to making possible wooden skyscrapers and more energy-efficient paper production, according to research published today in the journal Nature Communications. ̽��ֱ��study, led by a father and son team at the Universities of Warwick and Cambridge, solves a long-standing mystery of how key sugars in cells bind to form strong, indigestible materials.

We knew the answer must be elegant and simple. And in fact, it was

Paul Dupree

Paul Bica

Vanishing point

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Opinion: Can we save the algae biofuel industry?

Anonymous — Tue, 10 May 2016 11:18:31 +0000

Algal biofuels are in trouble. This alternative fuel source could help reduce overall carbon emissions without taking land from food production, like many crop-based biofuels do. But several major companies including Shell and ExxonMobil are seemingly abandoning their investments in this environmentally friendly fuel. So why has this promising technology failed to deliver, and what could be done to save it?

Algae are photosynthetic organisms related to plants that grow in water and produce energy from carbon dioxide and sunlight. Single-celled microalgae can be used to produce large amounts of fat, which can be converted into biodiesel, the most common form of biofuel. There are many possible ingredients for making biofuels, from corn to used cooking oil. But algae are particularly interesting because they can be grown rapidly and produce large amounts of fuel relative to the resources used to grow them (high productivity).

In the last decade or so, vast amounts of money have been invested in the development of algae for biofuel production. This made sense because, ten years ago, there was a need to find alternatives to fossil fuels due to the high oil price and the increasing recognition that carbon emissions were causing climate change. Algal biofuels were touted as the answer to these twin problems, and huge investment followed.

Unfortunately, things didn’t go quite to plan. Companies making algal biofuels struggled to retain their high productivity at a larger scale and found predators often contaminated their farms. They also found that the economics just didn’t make sense. Building the ponds in which to grow the algae and providing enough light and nutrients for them to grow proved too expensive, and to make matters worse the oil price has plummeted.

Beyond biofuels

But algae don’t just produce biofuels. In fact, algae are like microscopic factories producing all sorts of useful compounds that can be used to make an amazingly diverse range of products.

For example, algae can produce large amounts of omega-3 fatty acids, an important dietary supplement. This means it could be a sustainable, vegetarian source of omega-3, which is otherwise only available from eating fish or unappetising cod liver tablets. More generally, algae are excellent sources of vitamins, minerals and proteins, with species such as Chlorella and Spirulina commonly being consumed for their health benefits.

Another useful product that can be made from algae is bioplastic. Regular plastic is a product of fossil fuels and takes an extremely long time to break down, which makes it very environmentally unfriendly. Bioplastic from algae can be produced with low carbon emissions, or even in a way that absorbs emissions. Their use could help prevent the build up of plastic in the environment.

̽��ֱ��diversity of these products may be the key to finally developing algal biofuels. Many are high-value chemicals, selling for a much higher price than biofuels. So by combining them with biodiesel production, we could subsidise the price of the fuel and offset the high costs of algal cultivation.

This concept, known as a “biorefinery”, is part of a new wave of algae research that aims to overcome the issues of the past decade or so. We already know that oil refineries produce plastics, fibres and lubricants as well as fuels. Now we are hoping to develop algal biorefineries in exactly the same way.

Could health supplements like this be the solution to our biofuel problems? mama_mia/Shutterstock

Producing an algal biorefinery

To make this model cost-effective and sustainable, we would need to use waste sources of heat, carbon dioxide and nutrients to grow the algae. These are widely available from power plants, factories and water treatment plants and so could reduce some of the costs of growing algae. After making algal fuel, you’re left with lots of proteins, carbohydrates and other molecules. These can be converted into the kinds of products mentioned above, or used to produce biogas (another fuel source). This biogas can be sold or used at the biorefinery to produce heat for the algae, closing the loop and making the whole process more efficient.

It’s easy to see how this process could be a way forward for sustainable, profitable biofuel from algae. In fact, there are companies already applying this concept to their work. In 2014 Sapphire Energy, one of the world’s largest algal biotechnology companies, announced that they were diversifying their work to include nutritional supplements as well as biofuels. This move towards biorefinery is becoming more common and many firms diversifying their product lines.

Clearly, the algal biorefinery will not solve all the problems facing commercial algal cultivation today. There are still key issues facing the loss of yield at very large scales, and the contamination of algal cultures by predators that eat your crop of algae. These issues will only be solved by continued research efforts. However, biorefinery may well be the next step towards a future free from fossil fuels.

Christian Ridley, Research Associate in Plant Biotechnology, ̽��ֱ�� of Cambridge

This article was originally published on ̽��ֱ��Conversation. Read the original article.

̽��ֱ��opinions expressed in this article are those of the individual author(s) and do not represent the views of the ̽��ֱ�� of Cambridge.

Christian Ridley (Department of Plant Sciences) discusses why algae biofuel has failed to deliver, and what could be done to save this promising technology.

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Breeding better grasses for food and fuel

gm349 — Tue, 17 Jan 2012 10:31:03 +0000

Researchers from the Biotechnology and Biological Sciences Research Council (BBSRC) Sustainable Bioenergy Centre (BSBEC) have discovered a family of genes that could help us breed grasses with improved properties for diet and bioenergy.

̽��ֱ��research was carried out by a team from the ̽��ֱ�� of Cambridge and Rothamsted Research, which receives strategic funding from BBSRC. Their findings are published today (Tuesday 17 Jan) in the journal Proceedings of the National Academy of Sciences (PNAS).

̽��ֱ��genes are important in the development of the fibrous, woody parts of grasses, like rice and wheat. ̽��ֱ��team hopes that by understanding how these genes work, they might for example be able to breed varieties of cereals where the fibrous parts of the plants confer dietary benefits or crops whose straw requires less energy-intensive processing in order to produce biofuels.

̽��ֱ��majority of the energy stored in plants is contained within the woody parts, and billions of tons of this material are produced by global agriculture each year in growing cereals and other grass crops, but this energy is tightly locked away and hard to get at. This research could offer the possibility of multi-use crops where the grain could be used for food and feed and the straw used to produce energy efficiently. This is crucial if we are to ensure that energy can be generated sustainably from plants, without competing with food production.

Professor Paul Dupree, of the ̽��ֱ�� of Cambridge's Department of Biochemistry, explains, “Unlike starchy grains, the energy stored in the woody parts of plants is locked away and difficult to get at. Just as cows have to chew the cud and need a stomach with four compartments to extract enough energy from grass, we need to use energy-intensive mechanical and chemical processing to produce biofuels from straw.

“What we hope to do with this research is to produce varieties of plants where the woody parts yield their energy much more readily – but without compromising the structure of the plant. We think that one way to do this might be to modify the genes that are involved in the formation of a molecule called xylan – a crucial structural component of plants.”

Xylan is an important, highly-abundant component of the tough walls that surround plant cells. It holds the other molecules in place and so helps to make a plant robust and rigid. This rigidity is important for the plant, but locks in the energy that we need to get at in order to produce bioenergy efficiently.

Grasses contain a substantially different form of xylan to other plants. ̽��ֱ��team wanted to find out what was responsible for this difference and so looked for genes that were turned on much more regularly in grasses than in the model plant Arabidopsis. Once they had identified the gene family in wheat and rice, called GT61, they were able transfer it into Arabidopsis, which in turn developed the grass form of xylan.

Dr Rowan Mitchell of Rothamsted Research continues, "As well as adding the GT61 genes to Arabidopsis, we also turned off the genes in wheat grain. Both the Arabidopsis plants and the wheat grain appeared normal, despite the changes to xylan. This suggests that we can make modifications to xylan without compromising its ability to hold cell walls together. This is important as it would mean that there is scope to produce plant varieties that strike the right balance of being sturdy enough to grow and thrive, whilst also having other useful properties such as for biofuel production."

̽��ֱ��tough, fibrous parts of plants are also an important component of our diet as fibre. Fibre has a well established role in a healthy diet, for example, by lowering blood cholesterol. ̽��ֱ��team have already demonstrated that changing GT61 genes in wheat grain affects the dietary fibre properties so this research also offers the possibility of breeding varieties of cereals for producing foods with enhanced health benefits.

Duncan Eggar, BBSRC Bioenergy Champion said: “Recent reports have underlined the important role that bioenergy can play in meeting our future energy needs – but they all emphasise that sustainability must be paramount.

“Central to this will be ensuring that we can get energy efficiently from woody sources that need not compete with food supply. This research demonstrates how, by understanding the fundamental biology of plants, we can think about how to produce varieties of crops with useful traits, specifically for use as a source of energy.”

Newly discovered family of genes could help us breed grasses with improved properties for food and fuel.

Unlike starchy grains, the energy stored in the woody parts of plants is locked away and difficult to get at. Just as cows have to chew the cud and need a stomach with four compartments to extract enough energy from grass, we need to use energy-intensive mechanical and chemical processing to produce biofuels from straw.

Professor Paul Dupree, of the ̽��ֱ�� of Cambridge's Department of Biochemistry

Rowan Mitchell, Rothamsted Research

Plant cells, like these in wheat, are surrounded by thick walls where energy is locked up.

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̽��ֱ��hidden power of moss

amb206 — Thu, 22 Sep 2011 05:03:47 +0000

Moss is regarded as a menace by gardeners who seek to eradicate it from their lawns. Now researchers all over the world are exploring how moss, algae and plants could be used as a source of renewable energy in the future.

A team of designers and scientists at Cambridge ̽��ֱ�� will be exhibiting a novel moss table at the London Design Festival later this week. ̽��ֱ��prototype table will showcase an emerging technology called biophotovoltaics (BPV) which uses the natural process of photosynthesis to generate electrical energy.

Featuring biological fuel cells made from moss, the table has been created as a vision of the future by Alex Driver and Carlos Peralta from Cambridge’s Institute for Manufacturing and Paolo Bombelli from the ̽��ֱ��’s Chemical Engineering and Biotechnology Department.

Still at early stages, BPV has the potential to power small devices such as digital clocks. Low cost BPV devices may become competitive alternatives to conventional renewable technologies such as bio-fuels in the next ten years.

̽��ֱ��appeal of BPV lies in its ability to harness a natural process that takes place all around us. Photosynthesis occurs when plants convert carbon dioxide from the atmosphere into organic compounds using energy from sunlight. Plants use these organic compounds – carbohydrates, proteins and lipids – to grow.

When the moss photosynthesises it releases some of these organic compounds into the soil which contains symbiotic bacteria. ̽��ֱ��bacteria break down the compounds, which they need to survive, liberating by-products that include electrons. ̽��ֱ��table designed by the Cambridge ̽��ֱ�� team captures these electrons to produce an electrical current.

̽��ֱ��table is based on research into biophotovoltaics funded by the Engineering and Physical Sciences Research Council (EPSRC). This pioneering work involves collaboration between the Departments of Chemical Engineering and Biotechnology, Biochemistry and Plant Sciences at Cambridge ̽��ֱ��, and the Chemistry Department at Bath ̽��ֱ��. ̽��ֱ��research is led jointly byDr Adrain Fisher, Professor Christopher Howe and Professor Alison Smith at Cambridge, and Dr Petra Cameron at Bath.

Carlos Peralta said: “ ̽��ֱ��moss table provides us with a vision of the future. It suggests a world in which self-sustaining organic-synthetic hybrid objects surround us, and supply us with our daily needs in a clean and environmentally friendly manner.”

Looking into the future, possible applications for BPV include solar panels, power stations and generators. Currently at concept stage, these are envisaged as sustainable solutions to pressing problems across the world – including the growing need for energy and fresh water from vulnerable communities.

“A modular system of biological solar panels would be mounted on to the roof of a building to supply it with a portion of its energy requirements,” explained Alex Driver “A biophotovoltaic power station would comprise giant algae-coated lily-pads floating on the surface of the ocean near the coastline, generating energy for local communities. A biophotovoltaic generator would feature algae solar collectors mounted on floating buoys and anchored just offshore to generate energy and harvest desalinated water, which is a waste product of one of the chemical reactions occurring in the device.”

̽��ֱ��Cambridge team emphasised that the technology was at very early stages. “It will be a long time before a product powered by this technology will be commercially available,” said Dr James Moutrie, Head of the Design Management Group at the Institute for Manufacturing. “ ̽��ֱ��table we are exhibiting this week demonstrates the ways in which designers can play a valuable role in early stage scientific research by identifying commercial potential and is one of the outcomes from our Design in Science research project.”

Scientists at Cambridge ̽��ֱ�� are exhibiting a prototype table that demonstrates how biological fuel cells can harness energy from plants.

̽��ֱ��moss table provides us with a vision of the future. It suggests a world in which self-sustaining organic-synthetic hybrid objects surround us, and supply us with our daily needs in a clean and environmentally friendly manner.

Carlos Peralta

Institute for Manufacturing, ̽��ֱ�� of Cambridge

Close-up of the moss pots incorporated into a novel table developed at Cambridge ̽��ֱ��.

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Seeding growth: plant sciences

bjb42 — Sat, 01 May 2010 14:17:38 +0000

Increasingly, plants are recognised as being at the heart of sustainable solutions to many global concerns, whether it’s the need to secure food supplies, develop biofuels or tackle environmental issues. ‘Plant-related research is now much more prominent as a result of this new awareness,’ said Professor Sir David Baulcombe, Head of the Department of Plant Sciences and first incumbent of the newly created Regius Professorship of Botany. ‘We want to be in a position in Cambridge to step up to the mark and generate the understanding and applications needed to meet these challenges.’

Fortunately, Cambridge has a strong record in the study of plants, a record that is being strengthened by funding for new facilities and research in the Department of Plant Sciences, and by the ongoing construction of the Sainsbury Laboratory in the ̽��ֱ��’s Botanic Garden.

A long-term refurbishment programme within the Plant Science buildings in the centre of Cambridge has seen the addition of wet and dry research laboratories on two floors of the building. Three new Royal Society Research Fellows in the Department have been funded by £2 million from ̽��ֱ��Gatsby Charitable Foundation, which has also provided £2 million support for Professor Baulcombe’s research.

Added to this are the two new buildings. A £6 million Plant Growth Facility situated in the Botanic Garden, funded by the Science Research Investment Fund and ̽��ֱ��Gatsby Charitable Foundation, has provided much-needed space for cultivating and studying plants under controlled environmental conditions. Due for completion later this year is the magnificent Sainsbury Laboratory, which has been made possible through a gift by ̽��ֱ��Gatsby Charitable Foundation of £82 million, the largest single gift received by the ̽��ֱ�� since the launch of the 800th Anniversary Campaign.

From forests to fragments

̽��ֱ��study of plants has been transformed by the resources now available to biologists. In the Department of Plant Sciences, engineering principles are being applied to plant development and behaviour; computer modelling yields vast datasets on the spread of plant viruses or of genetically modified crops; sophisticated genetic tools and high-volume DNA sequencing are giving insight into how plant cells function and how they can be modified; and refined chemical approaches are opening up new routes for generating energy from plants.

̽��ֱ��exceptional breadth of research doesn’t reach just from genetics to biochemistry, and from evolution to ecology, but also from gigantic to miniscule. One example of the larger-scale research being undertaken in the Department is Dr Ed Tanner’s work on the Panamanian rainforest. For the past decade, Dr Tanner’s group has been looking at the effects of climate change on carbon and nutrient fluxes in lowland tropical rainforest.

Elevated CO₂ in the atmosphere increases the growth of trees, which produce more leaves that eventually fall from the canopy to the forest floor. Dr Tanner’s research group has demonstrated that this additional leaf fall has the net effect of mobilising carbon that was stored in the soil. ‘These data have environmental implications since they show that carbon in tropical soil is in dynamic equilibrium and that additions of carbon can destabilise some of the soil organic matter, causing increased release of CO₂’.

At the other end of the size range, many research groups aim to understand how plant cells work at the molecular scale. For example, research in Professor Baulcombe’s group investigates how plants regulate gene expression, and in particular the molecular mechanisms that enable plants to become disease resistant. ‘We have shown how the presence of small fragments of the genome of an infecting virus in a plant cell guide a plant protein to newly infecting virus genomes and silence them, stopping the plant from being re-infected by the same virus.’

Professor Baulcombe’s work on this mechanism of gene silencing, and the small interfering RNA molecules that achieve it, has been honoured several times over: the 2008 Lasker Award for Basic Medical Research, and this year’s Wolf Foundation Prize in Agriculture and the Harvey Prize. As well as providing new opportunities for engineering disease resistance in plants of agricultural value, gene silencing offers a tool for turning genes on and off in plants to help determine their function.

Plants for food and fuel

̽��ֱ��United Nations Food and Agricultural Organization has forecast that global food production will need to increase by over 70% by 2050 to feed the growing population. As more emphasis is placed on the role of plant science in providing long-term, sustainable answers, Cambridge researchers are investigating diverse areas that have applications in food security: how plant yields can be improved; how disease and pests can be controlled; and how plants can be re-modelled, for instance to adapt to growing in new environments.

Dr Julian Hibberd, named last year by Nature magazine as ‘one of five crop researchers who could change the world’, is working with a worldwide consortium of experts whose goal is to re-engineer rice to increase yields dramatically. With funding from the Bill & Melinda Gates Foundation, Dr Hibberd’s team is taking the pioneering approach of attempting to change the photosynthetic pathway used by rice into a more efficient pathway found in plants such as maize.

̽��ֱ��procedure is challenging but could reap great dividends, as Dr Hibberd explained: ‘It’s likely that dozens of genetic alterations will be needed to change the biochemistry, anatomy and biology of rice, but if we can produce higher-yielding rice this could dramatically alleviate potential food shortages of the future.’

Plants are also important as part of the spectrum of future energy resources. In the search for plant-based solutions, Cambridge’s Algal Bioenergy Consortium (ABC) is turning to algae, simple aquatic organisms from which the first land plants evolved 400 million years ago. ‘On many levels, algae make an excellent choice as a source of biofuel,’ explained Professor Alison Smith, one of the founders of the ABC. ‘Many species grow rapidly, can produce high levels of fuel molecules, and they are not a food crop.’

̽��ֱ��ABC is bringing together Cambridge-based algal physiologists and molecular biologists with engineers and chemical engineers, and is also working with industrial partners to test ideas that arise at the laboratory bench. One area of current investigation is the use of photovoltaic cells that ‘steal’ electrons from the algal photosynthetic process as a source of energy.

A new development: the Sainsbury Laboratory

̽��ֱ��Sainsbury Laboratory will provide state-of-the-art laboratory facilities for 120 scientists and 30 support staff dedicated to finding out how complex plants develop from a single egg cell, and to understanding how the information coded in their DNA leads to their growth and form – fundamental knowledge for understanding evolution and for improving crops. Together, research in the Laboratory and the Department of Plant Sciences will afford an enormously broad and integrated understanding of plants in Cambridge.

̽��ֱ��Laboratory will also provide a new home for the ̽��ֱ�� Herbarium, a unique collection begun by Professor John Stevens Henslow in 1821 and now containing a million specimens of historic and current research value. ‘In effect,’ said Professor John Parker, Curator of the Herbarium and Director of the Botanic Garden, ‘the Herbarium is returning home, to the Botanic Garden that was founded by Henslow over 160 years ago.’

At the ground-breaking ceremony for the new Laboratory last year, Lord Sainsbury, founder of ̽��ֱ��Gatsby Charitable Foundation, said: ‘This is one of the most exciting projects with which my Charitable Foundation has been involved. It combines an inspirational research programme, an historic site in the Botanic Garden and a beautiful laboratory designed by Stanton Williams, and I believe it will soon become a world-class centre of excellent plant science.’

‘ ̽��ֱ��new developments represent wonderful research opportunities,’ said Professor Baulcombe. ‘Not just for plant scientists in Cambridge but for underpinning much-needed information for progress in agriculture, energy and the conservation of biodiversity.’

For more information about research at the Department of Plant Sciences, please visit www.plantsci.cam.ac.uk/

̽��ֱ��study of plants is blossoming in Cambridge, with new facilities, new research and soon a major new institute.

Increasingly, plants are recognised as being at the heart of sustainable solutions to many global concerns.

Dr Beverley Glover

Flower

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