Yeast cells that produce anti-malarial drugs and chemical detectors based on nematode worm DNA. While this might sound like the stuff of science fiction, these are just two examples of how synthetic biology is being used to find sustainable, cost-effective solutions to address a range of health, environmental and energy issues.
Repackaging and redesigning biological systems
Synthetic biology is one of the most rapidly growing areas of modern science, combining biology and engineering to redesign biological pathways or systems, or to build new ones. The aim of this work is to engineer organisms that produce useful chemicals from inexpensive and renewable starting materials. These organisms, such as yeast (Saccharomyces cerevisiae) and the bacteria Escherichia coli, effectively operate as tiny biological factories that produce drugs, fuels and other chemicals, reliably, sustainably and cost-effectively. As a result, the field offers a wealth of potential for developments in healthcare, industrial biotechnology, plant research and beyond.
In the past few years Australia has seen something of a groundswell in interest in the field, resulting in the formation of Synthetic Biology Australasia (SBA), and the convening of the recent Cutting Edge Symposium on Synthetic Biology.
Organised by CSIRO and the SBA, the symposium provided 160 participants from academia, industry, government and regulatory bodies with the opportunity to hear from leading national and international speakers.
The symposium opened with a session exploring the social dimensions of this frontier discipline. Jane Calvert from the University of Edinburgh, a world leader in this area, and Australian expert Wendy Russell both agreed that
Science presentations discussed advanced applications of synthetic biology, including the production of the anti-malarial drug artemisinin in yeast; using carbohydrate feedstocks to produce 1,4-butanediol (a chemical intermediate used in automotive, electronic and apparel products) instead of energy-intensive petrochemical processes; and the role Macquarie University is playing in the international synthetic ‘Yeast 2.0’ project.
CSIRO researchers showcased the CYBERNOSE/CYBERTONGUE biosensing platform that can detect and measure odours and chemicals in a range of substances. The platform is based on re-engineered biological proteins, like smell receptors from nematode worms. The proteins emit a mix of blue and green light that changes when particular chemicals are present. Measuring the light allows for measurement of a range of substances, including spoilage enzymes in raw milk and other foods. Small molecules, such as sugars, amino acids and contaminants, can also be measured using the platform.
Omega-3 long-chain polyunsaturated fatty acids like EPA and DHA have critical roles in human health and development. Deficiencies in these fatty acids can increase the risk of cardiovascular and inflammatory diseases. CSIRO’s Plant Oils Engineering Group has successfully engineered the synthesis of DHA in oilseed plants by transferring a seven-gene algal pathway into canola. This produced DHA levels in the plants that exceed the amount typically found in bulk fish oil, potentially providing an alternative, safe and sustainable source of DHA.
CSIRO’s biocatalysis team is investigating new, environmentally friendly and efficient ways of making chemicals. They have developed nanomachine biocatalysts to produce pre-cursors of two anti-diabetic drugs. These nanomachines consist of bacterial enzymes that have been arranged in such a way that streamlines their activity. As a result, they can very efficiently convert glycerol, a low-cost feedstock, into the drug precursors. This work paves the way for cost-effective production of these, and other, pharmaceuticals.
As well as presentations from leaders in synthetic biology, symposium participants had the opportunity to hear from undergraduate students participating in the iGEM (International Genetically Engineered Machine) competition. This competition sees more than 200 teams from around the world develop new genetically modified organisms, including biocomputers, bioplastics and biosensors. Australian medal-winning teams from the 2015 competition presented their projects: optimising the expression of the enzyme ethene monooxygenase (University of Sydney); developing synthetic biology tools to engineer potential endosymbionts for mammalian cell hosts (University of New South Wales); and harnessing photosynthesis to produce renewable, environmentally friendly energy (Macquarie University).