Synthetic biology is a relatively novel multidisciplinary field of science in which biological systems and parts are rationally designed and engineered for particular outcomes. Owing to the significant depreciation in the cost of DNA sequencing and writing technologies within the field, the pace of scientific advancement within the field has begun to demonstrate the extent to which synthetic biology and its many applications can revolutionise industries, societies and economies. Ranging from the bioremediation of toxic industrial chemicals in our natural environment, to the development of complex biomaterials with carbon negative production processes and recently to the rewiring of human immune systems in the face of global pandemics, synthetic biology is touted to be on the verge of an inflexion point with human development. It's widespread promise is profound, and its continued research in new applications is of great interest to society across the public and private sectors in the face of new decarbonisation strategies for future peaceful and sustainable development.
Why do we need a circular economy?
The circular economy has become a recent buzzword across a multitude of multinational and start-up companies, as well as green governmental agendas. It captures the ideology of limiting the continued extraction of resources from our natural environment by harnessing the materials and resources that are currently in circulation within our economies, thereby eliminating the generation of waste and diminishing our carbon footprint and the pressure we exert on our ecosystems. This is in stark contrast to the functioning of our current economies, in which resources are intensively extracted at scale in a way that is unsustainable to future development. The waste generation of our current, take-make-waste linear economic model is immensely significant and requires the attention of novel design strategies to incorporate recycling and upcycling practices so as to avoid environmental destruction and indeed secure our own future on this planet.
Ref: UNIDO 2017, online at: https://www.unido.org/sites/default/files/2017-07/Circular_Economy_UNIDO_0.pdf and Cities in the Circular Economy: an initial exploration. Ellen Macarthur Foundation 2017. Circular Amsterdam. A Vision and Roadmap for the City and Region. | By Smart City Expo World Congress - Fira de Barcelona 2018 @SmartCityExpo @Circularsummit
Lignocellulosic biomass is one such waste stream of interest to this year's University of Edinburgh 2021 iDEC team. Being the most common polysaccharide on this planet, it is estimated that 1 billion tonnes of the common agricultural waste stream will be made available annually within the European Union[1]. However, in its polymeric form it is of little value due to its complex crystalline structure which has evolved to specifically withstand enzymatic and microbial attack [2]. The highly valuable glucose monomers are locked within the complex matrix and inaccessible to industrial processes that do not employ harsh, economically and environmentally unsustainable methods for their extraction [3]. Therefore, the majority of the waste material is either burnt or composted in favour of a conventional linear economic model. In realising the circular bioeconomy of the future, sugar feedstocks will become an increasingly valuable agricultural product, and with our global food production system already under strain by our ever-growing population, other sources of sugar production will be required for our society to maintain the health of our planet. Bioethanol is a highly recognised bioproduct and its production from second generation feedstocks such as lignocellulosic biomass stands at the forefront of a circular bioeconomy[4,5]. However, the pace of synthetic biology within industrial manufacturing capabilities promises a wide range of products which will require a vast amount of glucose to become available for the metabolic manufacturing revolution [6,7]. The sourcing of sugar from overexploited, high land and water intensive primary feedstocks will not work to produce these products, as the sustainability of the end-product reflects its manufacturing process. The implementation of waste streams using novel manufacturing technologies is an important research area and the primary motivation for the team's objectives.
What is 'the SuperGrinder'?
The University of Edinburgh 2021 iDEC team was initially conceived from the University's international genetically engineered machine (iGEM) competition team. With an eye towards the role synthetic biology can play in new sustainable manufacturing and waste processing practices, the team set out to devise a new concept for the reintroduction of important waste streams that are present on a large scale across our global society. Faced with a large global population on a small and strained planet, our focus is to limit the amount of resources that we extract from the natural environment by harnessing the resources that are already available to us in an industrialised society. However, some waste streams are difficult to manage due to their biologically complex structure and recalcitrant nature, limiting their recyclability within our current infrastructure framework. The University of Edinburgh 2021 iDEC and iGEM teams have therefore designed a novel machine, the SuperGrinder, which merges enzymatic and mechanical forces to enhance the degradation potential of these waste streams in a way that is conducive to further downstream and upcycling purposes.
References:
[1] S2Biom Project Grant Agreement n°608622 D8.2 Vision for 1 billion dry tonnes lignocellulosic biomass as a contribution to biobased economy by 2030 in Europe Delivery of sustainable supply of non-food biomass to support a “resource-efficient” Bioeconomy in Europe. 2016 [cited 2021 Aug 12]; Available from: www.s2biom.eu.
[2] Abdel-Hamid AM, Solbiati JO, Cann IKO. Insights into Lignin
Degradation and its Potential Industrial Applications. Adv Appl
Microbiol. 2013 Jan 1;82:1–28.
[3] Baruah J, Nath BK, Sharma R, Kumar S, Deka RC, Baruah DC, et al. Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products. Front Energy Res. 2018 Dec 18;0(DEC):141.
[4] Abdel-Hamid AM, Solbiati JO, Cann IKO. Insights into Lignin Degradation and its Potential Industrial Applications. Adv Appl
Microbiol. 2013 Jan 1;82:1–28.
[5] Baruah J, Nath BK, Sharma R, Kumar S, Deka RC, Baruah DC, et al. Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products. Front Energy Res. 2018 Dec 18;0(DEC):141.
[6] Delisi C. The role of synthetic biology in climate change mitigation. [cited 2021 Aug 12]; Available from: https://doi.org/10.1186/s13062-
019-0247-8
[7] Voigt CA. Synthetic biology 2020–2030: six commercially-available products that are changing our world. Nat Commun 2020 111 [Internet]. 2020 Dec 11 [cited 2021 Aug 12];11(1):1–6. Available from: https://www.nature.com/articles/s41467-020-20122-2
