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Bricks from bacteria
Bricks, grown at room temperature from bacteria, sand, and urea, could drastically reduce the construction industry’s carbon footprint, their developer claims.
The bio-manufactured bricks, created by Professor Ginger Krieg Dosier, at the American University of Sharjah in Abu Dhabi, UAE, are produced by layering sand with Sporosarcina pasteurii, a non-pathogenic common soil bacterium naturally found in wetlands.
The bacteria are mixed with a solution of urea and calcium chloride. They use urea as a source of energy, producing ammonia and carbon dioxide, increasing the pH level of the solution, says Dosier. The rise in pH forms a mineral precipitate, combining calcium chloride with carbon dioxide. The bacteria can then act as nucleation sites, attracting mineral ions from calcium chloride to the cell wall, forming calcite crystals. The mineral growth fills gaps between the sand grains, cementing them.
Rather than being fired in a kiln, the chemical reaction dries and hardens the material at temperatures of 20-30ºC, reducing energy costs. Dosier claims that the resulting material is as strong as a fired clay brick.
Wetting, drying, freeze-thaw and abrasion resistance tests are yet to be conducted, as is a comparison with un-fired clay bricks in terms of their eco-credentials.
Up to now, the process has only been tested using sand from the UAE, but Dosier is keen to test aggregates from other countries for compatibility with the bacteria. ‘These soils will include small percentages of clay’, she explains, ‘But they will need to be specifically graded for this process as fine particles will block [bacteria] penetration.’
While the new brick presents countless design possibilities, there are hurdles in terms of large-scale production. Firstly, this process is slow (taking one week to dry and harden) and, secondly, the chemical processes release ammonia and a small amount of carbon dioxide. Microbes convert the ammonia to nitrates, which can poison groundwater. To solve this problem, Dosier plans to design a system that will capture emissions and recycle them back into the production cycle.
Pete Walker, Professor of Innovative Construction Materials at the University of Bath, UK, sees promise in the work, but recognises there is still plenty of research to be done.
‘A rigorous lifecycle assessment [is needed] to make sure there are no hidden negative environmental impacts,’ he says. ‘But perhaps the biggest concern relates to any potential health risks. What happens if not all the bacteria is converted or activated in the chemical process? Are these bacteria going to cause any concern to the structure of the building or its inhabitants?’
Walker also insists that the technique has to be economically viable before it can make its way into industry, and these biological bricks currently cost over five times the amount of one made from clay (US$2.70 per bio-manufactured brick compared to US$0.5 for a traditional clay brick).
Dosier says she is working to address these issues, and is looking for industrial partners to take the work further.
A radical departure from current means of human production is needed and possible through the study and mimesis of nature.
A Radical Means is a microbally induced casting procedure, which presents the bacteria Sporosarcina pasteurii as a method for cementing natural granular materials using minerals as a binding agent, for the creation of artefacts. This methodology suggests a radical future vision of industrial manufacturing, which is able to produce and form mineral composites at biological temperatures.
Johanna Sim’s Statement
Tinkering with Nature’s Circuits
Synthetic biology – new, fluid and ever-changing is blurring the boundaries between biology, chemistry, engineering, and computing. This is a place where cameras are built from bacteria, and where plans are being made to create truly artificial life, built by radically redesigning the most fundamental interface where science meets nature.
By taking existing yet constantly evolving science and using it to penetrate a process as familiar and universal as the morning ritual, I hope to illustrate the huge impact these emerging technologies can have in our daily lives. And what ethical questions will be raised by the literal integration of new technologies into our most private even sacred spaces? Our homes, our minds, even our bodies?
FROM squid and fire flies bacteria feed form nutiants in milk weed and cotton to and grow in biotechnology harnesses the enzyme called luciferase and produces bioluminecence can be mounted into cylinders. or into fabrics using polylaminate fabrics where glowing bacteria are loaded into the fabric and sandwished inbetween perimable shell..
Many of the artworks that I make are created through the design and construction of controlled environmental spaces. In these environments I transform and refine a variety of sculptural artifacts much as one might train the growth of a Bonsai tree. My desire is that a person encountering this artwork will consider the idea of nature within a frame of social and historic contexts.
Below is an image of Mycotectural Alpha, a tea house grown from the fungus Ganoderma lucidum. Click on the top of the art menu above for more images of this new work.
Ethics and aesthetics as criteria for innovation: A design research study of biological art and digital architecture Funded ARC Grant 2009-2011
This project aims to understand innovation through design research, namely by engaging and reflecting on the activity of designing. It will develop and study a network of artists and designers in an emerging field of innovative practice, to capitalize on Australian expertise, and capture new knowledge about designerly ways of knowing that underpin innovation. Australia must innovate to tackle issues such as climate change, characterised by uncertainty, instability, uniqueness, and value conflicts. The research develops the central claim of design research, namely that design is a discipline with specific forms of knowledge, and specifically considers the role of this knowledge in the vital area of innovation. ARC grant Chief investigators: Dr Pia Ednie-Brown, Dr Andrew Burrow and Prof. Mark Burry of RMIT University, and Oron Catts, SymbioticA, UWA
Spider silk has long represented the holy grail of biomimetic materials. By weight this thread is three times stronger than steel. However, as alluded to by the technicians in Get Smart, our “inability to domesticate spiders has driven numerous attempts to artificially manufacture spider dragline silks for industrial and medical applications.”1 In other words, spider wrangling has never been a viable profession.
Overcoming the bioengineering challenge of synthesizing spider silks has proven difficult at many levels. First there is the challenge of isolating and cloning the spider silk genes. Given the high number of repetitive regions that give the silks their strength and elasticity, traditional cloning strategies are prone to failure. Second, once these genes have been cloned within bacterial hosts, expressing and collecting the proteins is no simple matter. Most bacteria aren’t optimized to deal with highly repetitive sequences and consequently generate truncated versions of these proteins. Third, even after the proteins are expressed and purified, they’re not spider silk but merely a blob of protein with potential called “unspun silk dope.”
Once spiders have their unspun silk dope stored in their glands, they spin it by pulling it through a narrow gland called a spinarette in a process engineers call extrusion. By extruding the silk, water is removed from the dope as the silk makes the transition from a gel to a solid fiber about 2.5–4 microns thick (about 30 times thinner than the width of a human hair.) Spiders are uniquely equipped to spin these mighty mite threads, but so far synthetic spinning by extrusion has generated threads that are no smaller than 10–60 microns thick.
Despite the challenges, the amazing properties of these biomaterials make them an attractive target for bioengineers. Not only are spider silks highly elastic, lightweight, and extremely strong, some have even been shown to facilitate nerve regrowth in mammalian cells. Consequently, teams of people around the country and the world continue working to generate synthetic spider silks.
In one of the more promising recent attempts, an international team described how they generated and spun recombinant spider-like proteins. Spider silk proteins alternate in composition between crystalline and amorphous regions. The exact sequence of these regions dictates the mechanical properties of the spider silk. Starting with spider silk-like crystalline domains flanked by elastic and helical regions, the researchers cloned various proteins into Escherichia coli expression vectors. They were then able to express (produce) the silk proteins by introducing these DNA cassettes called vectors into the E. coli bacterial host. To allow for sequence diversity and easy scale-up, the researchers used a special cloning trick to make repetitive cloning of these subunits simple. This neat scheme allowed them to “mix-n-match” domains to create a wide array of protein combinations from the subunits.
To purify the spider silk-like proteins from all the other proteins produced by the bacteria, the team cloned a special removable protein sequence called a polyhistidine-tag to the end of the protein. This sequence of ten histidine amino acids binds to metals such as nickel and cobalt. The silk proteins were separated from the bulk of the cellular proteins through a process called immobilized metal affinity chromatography (IMAC). Running the cell lysates (broken, open cells) over a nickel resin with the histidine-tag immobilizes the silk-like proteins on the column while the non-specific proteins were washed away. The silk-like proteins were then recovered by adding a protease solution that released them from the column-bound histidine-tag.
The team then dissolved the proteins into deionized water and HFIP (Hexafluoro-2-propano), an organic solvent commonly used to solubilize biopolymers. The silk dope was extruded through a stainless-steel spinarette into an isopropanol bath to create uniform spider silk-like fibers. This process took a mere forty days from start to finish but would be longer if researchers wanted more than two “mix-n-matched” domains in the final silk. However, once the desired sequence is cloned into in bacterial vectors, the harvesting and spinning process can be completed in approximately 15 days.
Finding ways to readily produce spider-like silks will continue to be a hot topic in the fields of biomimetics and biomaterials. The value of this special material, combined with the difficulty encountered by spider wranglers in obtaining natural silks, demands a synthetic alternative. However, as we learn from nature and attempt to repeat the wonders found therein, the intricacy of the solutions is astounding. A simple garden spider can achieve in minutes what takes teams of people using toxic chemicals and rigorous protocols weeks to accomplish. Even Hollywood movies recognize the challenge of making spider silk.
But spiders don’t need a whole host of technicians and scientists to catch their next meal. God has endowed them with unique abilities to fulfill their role as predators of the insect world. By learning from nature, not only can we obtain new technologies to benefit mankind, but we can see how God has provided for even the lowliest of creatures by granting them extraordinary traits. In Matthew 6 Jesus reminds us how valuable we are in comparison to the birds and the flowers. In light of how the Creator has provided for the spiders, we might paraphrase the analogy, “Consider the spiders of the attic and the wild, they have no formal training, yet they weave beautiful webs that yield them dinner. How much more will God provide for you?”
Destroying bacteria with bioactive packaging paper
Paper treated with a test bioactive ink changes colour when exposed to a test solution Canadian researchers are developing a bioactive packaging paper that they believe will detect and kill pathogens present in food and drinks in a matter of seconds.
A consortium of 10 universities has formed the Sentinel Bioactive Paper Network, which is investigating biologically active chemicals to produce paper that can detect and deactivate bacteria and viruses such as E-coli and salmonella. This form of rapid pathogen detection has not been created before – normally samples take hours or days to be characterised in a lab. This would provide a cheap yet effective way of testing and decontaminating food or drinking water.
‘We are investigating a variety of detection technologies including antibodies, enzymes, bacteriophase and DNA aptamers. These are standard biochemical approaches to detecting pathogens. The challenge is to make them function on paper without special storage conditions and instruments,’ explains Professor Robert Pelton, Scientific Director of Sentinel, of McMaster University.
Using standard paper, the group is working on a bioactive ‘ink’ that could be printed, coated or impregnated onto or into paper using readily available techniques. Working with existing bacteria-sensing substrates, researchers are trying to identify key structural properties, such as porosity, surface chemistry and fibre type, to produce the right ink. Substances such as bleach would be added to destroy the bacteria.
‘Destruction is relatively easy,’ says Pelton. ‘Detection is more difficult.’ The ink would be specified to identify individual pathogens such as E-coli by binding to them and producing a detectable response.
Paper was chosen as the base material because it is environmentally friendly and offers technical advantages over plastic film, explains Pelton. ‘Paper can act as a filter to isolate small molecules from large particles or cells, perform chromatographic separation, and it is hydrophilic and thus more protein-friendly than plastic.’
The trickiest part of the programme has been incorporating the biologically active chemicals into paper, and keeping them alive during the drying and aging process. Thus far, ink-jet printing has proven the most promising as it is currently used for patterning other bioactive molecules onto substrates. Fuji-Dimatix, an ink jet manufacturer, and Sun Chemical, a producer of ink, have been working with Sentinel to develop this technique.
The Network, which is operating on a CAD$7.5m grant from Canada’s Natural Sciences and Engineering Research Council and three million dollars from industrial partners, see the paper being used in food packaging or paper towels. There are, however, some issues that need to be addressed, adds Pelton. Paper degradation in liquids means that wet strength resins will need to be added, which could interfere with bio-detection.
‘By 2010, we hope to have demonstrated paper-supported pathogen detection. We also expect that our industrial partners will bring the first bioactive paper products to the marketplace.’
Scientists have demonstrated that large groups of bacteria can turn microgears millions of times larger than themselves, showing potential for “smart” biomechanical systems.
Scientists from Northwestern University and the U.S. Department of Energy’s Argonne National Laboratory observed several hundred microbes with random movement gather to push the spokes of a microscopic gear. With multiple gears arranged in a system, the bacteria — the common Bacillus subtilis — demonstrated synchronous movement.
Interestingly, the research team could manipulate the speed of the mechanical movement by controlling the amount of oxygen in the suspension solution: reduced oxygen naturally slowed the activity of the aerobic bacteria; reintroduced oxygen “woke” the bacteria up.
Eliminating the oxygen completely put the bacteria into a kind of “sleep” that stops them completely.
The team’s findings could lend insight into the design of “smart materials” — bio-inspired, dynamically adaptive materials made of a combination of bacteria or man-made nanorobots and hard materials that could be used to repair damage or power microdevices.
The bio-manufactured bricks, created by Professor Ginger Krieg Dosier, at the American University of Sharjah in Abu Dhabi, UAE, are produced by layering sand with Sporosarcina pasteurii, a non-pathogenic common soil bacterium naturally found in wetlands.
The bacteria are mixed with a solution of urea and calcium chloride. They use urea as a source of energy, producing ammonia and carbon dioxide, increasing the pH level of the solution, says Dosier. The rise in pH forms a mineral precipitate, combining calcium chloride with carbon dioxide. The bacteria can then act as nucleation sites, attracting mineral ions from calcium chloride to the cell wall, forming calcite crystals. The mineral growth fills gaps between the sand grains, cementing them.
Rather than being fired in a kiln, the chemical reaction dries and hardens the material at temperatures of 20-30ºC, reducing energy costs. Dosier claims that the resulting material is as strong as a fired clay brick.
Wetting, drying, freeze-thaw and abrasion resistance tests are yet to be conducted, as is a comparison with un-fired clay bricks i Up to now, the process has only been tested using sand from the UAE, but Dosier is keen to test aggregates from other countries for compatibility with the bacteria. ‘These soils will include small percentages of clay’, she explains, ‘But they will need to be specifically graded for this process as fine particles will block [bacteria] penetration.’
While the new brick presents countless design possibilities, there are hurdles in terms of large-scale production. Firstly, this process is slow (taking one week to dry and harden) and, secondly, the chemical processes release ammonia and a small amount of carbon dioxide. Microbes convert the ammonia to nitrates, which can poison groundwater. To solve this problem, Dosier plans to design a system that will capture emissions and recycle them back into the production cycle.
Pete Walker, Professor of Innovative Construction Materials at the University of Bath, UK, sees promise in the work, but recognises there is still plenty of research to be done.
‘A rigorous lifecycle assessment [is needed] to make sure there are no hidden negative environmental impacts,’ he says. ‘But perhaps the biggest concern relates to any potential health risks. What happens if not all the bacteria is converted or activated in the chemical process? Are these bacteria going to cause any concern to the structure of the building or its inhabitants?’
Walker also insists that the technique has to be economically viable before it can make its way into industry, and these biological bricks currently cost over five times the amount of one made from clay (US$2.70 per bio-manufactured brick compared to US$0.5 for a traditional clay brick).
Dosier says she is working to address these issues, and is looking for industrial partners to take the work further.
