Spider silk secrets unraveled
For years, scientists have struggled to unravel the secrets of spider silk. Weight for weight, spider silk is stronger than steel and can absorb 10 times more energy before breaking than bullet-proof Kevlar. Yet no one has been able to recreate these silk fibres in the laboratory, as fibres made from pure silk proteins are much weaker. But researchers in Germany have now homed in on the region of the silk protein that is responsible for efficient fibre assembly and storage (Nature, 2010, 465, 239) – knowledge that could be key to producing them for ourselves.
Spider silk owes its strength to the alanine-rich parts of the protein structure, while its elasticity stems from other amorphous glycine-rich regions. In the spider silk gland, the proteins are kept separate in solution because the conformation of this end region directs the hydrophilic regions outwards. As the spider spins its silk, this region unfolds so that the proteins shift to a new configuration. As they flow through the spinneret, shear forces cause them to align, creating strong, elastic bands. Researchers at the Universitäts of Bayreuth and München who made the discovery liken the region to a ‘molecular switch’, which also explains why interlinking is prevented during fibre storage (C&I, 2010 10, 9).
Universal flu vaccine
Annual flu injections could become a thing of the past after scientists in the US developed a ‘universal’ flu vaccine. Tests with mice showed that the vaccine is effective against multiple strains of flu, including the 1968 pandemic flu virus and H5N1 bird flu strains from the 2008 outbreak (C&I, 2010, 20, 10). The researchers from the Mount Sinai School of Medicine and the Scripps Research Institute targeted part of a specific protein found on the outside of flu viruses, using a synthetic peptide vaccine. This stalk region of the haemagglutinin protein is known to elicit the production of antibodies that protect animals against many different flu strains. Flu viruses are covered in two proteins – haemagglutinin and neuraminidase – against which vaccines typically attempt to raise an immune response. Unusually, the protein stalk of haemagglutinin is highly conserved and does not significantly mutate, which explains why other vaccines are needed seasonally.
Synthetic biology solves gout
Synthetic biology has provided a neat solution to the problem of gout – and could signal a new approach to the treatment of other medical ills. Researchers from ETH Zurich in Switzerland prepared cells containing a network of genes including those coding for a modified protein from Deinococcus radiodurans, which triggers production of a fungus-derived urate oxidase enzyme (Nature Biotechnology, doi: 10.1038/nbt.1617). This enzyme, which is absent in man, helps to keep in check levels of uric acid – which causes the painful joint condition as it crystallises out at blood concentrations above 6.8mg/dl. The researchers encapsulated the cells in a seaweed gelatine capsule to protect them from the immune system, before administering them to mice lacking the enzyme. Uric acid levels in the blood and urine were slashed and crystals in the kidneys were dissolved.
Polystyrene from waste
In June 2010, UK firm Axion Polymers made waves with the introduction of Axpoly PS13, a recycled polystyrene derived from retail packaging waste – the first European polymer product with the Carbon Reduction Label after evaluation by the UK Carbon Trust. The polymer’s arrival is down to what Axion says is the UK’s ‘most innovative, well-engineered sorting and separation process’. Fully recyclable, low carbon polymers are expected to become increasingly popular as customers look to make more sustainable purchasing options. Axion scooped the prize for top sustainable technology at the 2010 IChemE awards.
World’s first synthetic cell
In work that raises questions about the very nature of life itself, scientists have created the world’s first synthetic cell in the laboratory. JCVI SYN 1.0 was created by scientist and human genome sequencing pioneer Craig Venter and colleagues, from ‘off the shelf’ chemicals and a hollowed out bacterium (Science, doi: 10.1126/science.1190719).
To make the cell, the researchers created a synthetic genome by joining up more than 150 pieces of chemically manufactured DNA 6000 base pairs long. These were glued together with the help of yeast cells and inserted into the shell of the Mycoplasma capricolum bacteria, which had been stripped of its nucleus. However, the new cell would not ‘boot up’ until the researchers had carried out a couple of further steps. First, they methylated the DNA to protect the DNA from enzyme attack. Secondly, they needed to correct a tiny error in a gene involved in DNA replication, introduced after the genome had been made (C&I, 2010, 11, 5).
The resulting cell was then able to metabolise and replicate just like Mycoplasma mycoides – the bacteria whose genome the group had artificially created. Since its creation JCVI SYN 1.0 has undergone more than a billion self-replication steps; each cell contains the names of all of the researchers who created them – encoded in their genomes.
Greetings from electrochromic inks
Printable colour-changing inks that switch colour by on application of a tiny electrical charge have been developed by Irish firm Ntera, a spin-out from University College Dublin. The colour-changing displays are made by screen printing multiple layers of ink onto the desired surface and applying a self-sealing electrolyte to the surface. Application of as little as 1V causes the display to change colour. And because the display is a capacitor, the charge, and therefore the colour, remains. Shorting the display returns the electrochromic ink to the original state (C&I, 2010 5, 10). One of the biggest potential applications could be smart labels for goods, allowing retailers to change the price, for example, during a sale.
Biofuels made by bacteria
New routes to produce biodiesel in bacteria rather than from vegetable oils have been developed that promise to cut the cost of biofuels. Global biodiesel consumption is more than 2bn gallons/ year. The fatty esters that comprise biodiesel are typically produced from vegetable oils, so competing with food crops and potentially driving up food prices. Earlier in 2010, however, researchers from the University of California, US, reported engineering Escheridia coli bacteria to produce biodiesel fatty esters from glucose, without the need for other carbon sources (Nature, 2010, 463, 550). They then engineered the same strain to express hemicellulases, which could pave the way for producing biodiesel from waste cellulosic biomass. The researchers redirected the E. coli fatty acid metabolism to produce more fatty acids, while expressing more esterification enzymes (C&I, 2010, 3, 5).
Easy carbon footprint calculator
A carbon calculator developed by chemical engineers at Manchester University, UK, clinched the top prize at this year’s IChemE 2010 innovation and excellence awards. The CCaLc software helps firms to measure and reduce their carbon footprint at minimum cost and was developed with more than 20 industry partners. It helps companies estimate their carbon footprint along their supply chain and identifies carbon hotspots and opportunities for improvement. Unlike other carbon footprinting tools, CCaLc is claimed to be easy to use and takes a whole lifecycle approach, which makes it versatile across many industries. Launched in May 2010, it has been used by more than 350 organisations worldwide and is recommended as a preferred carbon footprint calculator by the UK’s Industrial Biotechnology Innovation and Growth Team.
Blood cells directly from skin
In November 2010, newspapers worldwide ran the story that researchers in Canada had made human blood cells directly from skin cells – technology that could be in use in the clinic within a few years. It could mean that patients undergoing surgery or requiring a transfusion will receive blood made from their own skin cells.
The technology’s novelty, according to its discoverers at McMaster University in Canada, lies in the fact that, unlike previous work to make blood from skin cells, it does not proceed via stem cells (Nature, doi: 10.1038/ nature09591). It should therefore be safer and more efficient than earlier approaches, and also has the advantage that it produces adult rather than fetal blood cells. Researchers were able to carry out the transformation using a chemical cocktail that allowed the cells to jump directly to immature blood cells.
‘Producing blood from patient’s own skin cells has the potential of making bone marrow transplant HLA matching and paucity of donors a thing of the past,’ said Cynthia Dunbar, head of the hematology branch at the US National Heart, Lung and Blood Institute.
Thorium fuelled nuclear reactor
Engineering firm Aker Solutions has designed a concept nuclear reactor fuelled by thorium, which could dramatically cut waste and the risk of nuclear proliferation. Several countries are now investing in research to develop nuclear reactors based on thorium, which is more abundant and so should be less expensive than uranium. Thorium reactors burn waste actinides, including plutonium generated in uranium reactors, increasing power generation while at the same time reducing problem waste. And using thorium avoids the need for expensive uranium enrichment processes, also employed to make weapons-grade materials, so improving security. Aker won the IChemE 2010 energy award for the reactor development and claims that the 600 MW accelerator-driven thorium reactor (ADTR) is competitive with conventional reactors.
Atom smashers recreate early Universe
Scientists have carried out an experiment to recreate conditions in the first instants after the Universe was formed following the ‘Big Bang’ nearly 14bn years ago.
On 7 November 2010, researchers at CERN’s Large Hadron Collider in Switzerland carried out their first atom smashing experiments with lead ions, at temperatures in excess of 12 trillion degrees and involving powerful magnets to propel the ions around a 27km circular tunnel before smashing them together at enormous energies.
One objective will be to produce tiny quantities of quarkgluon plasma – thought to be the earliest form of matter – and to study its evolution into the kind of matter that makes up the Universe today.
The exploration will also shed light on the ‘strong interaction’ – the force that binds particles called quarks into bigger protons and neutrons.
Fuel cell for fine chemicals
Fine chemicals could be produced more cheaply and with less waste in future thanks to a new type of fuel cell developed by researchers at ETH-Zurich in Switzerland. The group’s organometallic fuel cell (OMFC) comprises a rhodium complex that catalyses the oxidation of alcohols directly into aldehydes and then carboxylic acids, while usefully generating electricity at the same time (Angewandte Chemie, doi: 10.1002/ anie.201002234).
Conventional routes to produce fine chemicals typically produce copious amounts of waste; for every tonne of lactic acid synthesised, for example, the same amount of calcium sulphate waste is produced. Disposal of this waste can often be the most costly part of the process (C&I, 2010 19, 9). Using an OMFC should not only be much cleaner, but it would also generate clean, green electricity. The researchers are now looking to optimise the technology and lower costs by reducing the catalyst loading and looking at alternative metals to replace expensive rhodium.
Biofuels without blending
The relatively low energy density of biofuels such as bioethanol makes them of little use onboard aircraft. It also means they have to be blended with large amounts of energy dense fuels such as petrol. Earlier in 2010, however, researchers reported making a new route to make jet fuel from gamma-valerolactone (GVL), an organic compound derived from waste biomass, by converting it into butene (Science 2010, 327, 1110). They then used a straightforward petrochemical processing method to link the butene into large alkane chains. The high energy density of the final product means that it could be a useful aviation fuel and should replace hydrocarbon fuels without blending (C&I, 2010, 5, 11).
Strongest bonds are broken
Researchers have reported finding a way to break the two strongest chemical bonds – in molecular carbon monoxide and nitrogen – by using a transition metal complex. A catalyst based on such a complex could potentially lead to a new less energy intensive route to produce fertilisers, biofuels and other chemicals (C&I, 2010, 1, 10). The complex, made by chemists at Cornell University, US, comprises a hafnium metal core surrounded by cyclopentadienyl ligands. Adding one to one ratios of carbon monoxide and molecular nitrogen led to the formation of nitrogen-carbon and carbon-carbon bonds. These reactions occur at ambient temperatures and relatively low pressures of up to 4 atmospheres. Treating the resulting products with acid results in either ammonium chloride or oxamide – two important fertiliser ingredients – depending on the substrate concentrations used (Nature Chemistry, doi: 10.1038nchem.477). The conventional process to make fertilisers is by the Haber-Bosch process, which involves reacting atmospheric nitrogen at temperatures above 500oC and pressures up to 250atm. Although the hafnium complex itself could not offer a viable alternative route – as it is not catalytic and each reaction needs one complex – a catalyst variant could potentially be very valuable, researchers speculate.
Low fat full-flavour chocolate
C&I scooped the story two years ago (2008, 22, 8), but Birmingham University researchers have now been recognised with an IChemE 2010 food and drink award for developing chocolate with 16% less fat that retains all the taste and mouth-feel of full fat full fat bars. The researchers borrowed an idea used in creating low fat margarines to make cocoa butter emulsions containing tiny droplets of water of around 3 micrometers in size, below the detection limits of the tongue. The water droplets are encased in solid fat crystal shells and so prevented from mixing with other ingredients including sugar.
Reverse osmosis for London
Officially opened in June 2010, The Thames Gateway Water Treatment Works is the UK’s first largescale reverse osmosis water treatment plant, providing 150m L/day of potable water to back up London’s water supply. The plant, for which Thames Water won the IChemE water award 2010, is the first to use a four-stage reverse osmosis process. It treats brackish water of varying temperature, salt concentration and organic content from the Thames estuary and transforms it into the highest quality treated water. Renewable energy generated on site provides 100% of the plant power.
Sweeter taste of success
A new sweetener enhancer found in nature promises to halve the amount of sugars in food without affecting its taste – which should be good news post-Christmas. Flavour ingredients firm Redpoint Bio’s RP44, found in the herb Stevia, was granted Generally Recognised as Safe (GRAS) status in the US this summer and is licensed to International Flavors and Fragrances. In tests, sucrose solution with 285ppm RP44 was found to taste like a 7.5% sucrose solution, while a carbonated cola with high fructose corn syrup equivalent to 8% sucrose and 190ppm RP44 tasted like it contained nearly 11% sugar (C&I, 2010 3, 7). Natural products currently account for less than 5% of global sweetener sales, but have big potential owing to concerns over the safety of artificial varieties, according to market research firm Koncept Analytics.
Stem cell trial firsts
The world’s first human embryonic stem cell trials, as well as the first neural stem cell therapy trial in stroke patients, got under way during 2010 on both sides of the Atlantic. In the US, California based biotech firm Geron saw the start of trials of its GRNOPC1 therapy targeted at spinal cord injury in October 2010. Participants in the trial are newly injured patients, while the main aim is to assess safety. In the UK, Surreyheadquartered ReNeuron’s ReNOO1 cell therapy commenced trials for the treatment of patients disabled by stroke in November 2010. The trial, which is being carried out in Scotland, involves injecting neural stem cells into patients’ brains to repair damaged areas, although the focus will again initially be on safety.
It has been described as ‘an exceptionally well designed bucket’. But the Groasis waterbox is an irrigation-free plant incubator that promises to help solve the world’s burgeoning water, climate and food challenges. Named as ‘Best of what’s new innovation of the year’, the waterbox promises to restore eroded landscapes to productive fertile forests by conserving water and reducing evaporation, according to its inventors at AquaPro Holland. It delivers exactly the right amount of water needed by the plant daily via a wick to the roots of the young tree. ‘In this way a heavy rain shower of 10 minutes once a year can be divided to the plant over 365 days. This gives the young plant enough time to search for capillary water deep into the soil.’
Environmentally friendly fashion could take a new twist after researchers have come up with a recyclable fabric that can be sprayed directly onto the body to create clothes. The clothing in a can comprises a solution of fabric fibres, solvent and polymer that forms a skin-tight layer after being applied to skin, whereupon it gradually separates without sticking to hair or other material so that it can be taken on and off like regular clothing (C&I, 2010, 18, 8). A regular T-shirt takes around 15 minutes to form, according to its codevelopers Paul Luckham at Imperial College, London, and Manel Torres, a Spanish fashion designer. After wearing, the garments can simply be re-dissolved and reused.
Graphene lights the way ahead
Lighting displays that can be rolled out like wallpaper across walls and ceilings could be cheaper and easier to produce using graphene – single atom-thick sheets of carbon, according to new research in February 2010. Swedish and US researchers reported making a light-emitting electrochemical cell (LEC) with a graphene cathode and an anode of conductive organic dyes (ACS Nano, doi: 10.1021/ nn9018569), a device that could lead to large area lighting displays made from plastic. The graphene LEC produces similar light intensity, at similar levels of energy consumption, to organic light-emitting diodes (OLEDS), which are already being developed for such large area displays (C&I, 2010, 4, 5). Unlike OLEDs, LECs probably won’t be suitable for moving displays, such as TVs, because they take too long to switch on, but they should be cheaper as they don’t need expensive indium tin oxide, and can also be made from solutions, which is helpful for large scale roll-to-roll printing processes.