Sustainable futures
Microbial gas fermentation: a carbon-negative, sustainable route to biofuels, bioplastics and industrial chemicals at scale
There has never been a more urgent need to tackle greenhouse gas (GHG) emissions and to create sustainable, environment-friendly, circular systems for organic chemical production. Breaking reliance on petrochemical reserves is a necessity driven by dwindling supplies, consumer demand and the inherent climate change problems caused by adding yet more carbon into our world. As we transition from the age of fossil resources to the Age of Biology, there is huge potential for biomass and greenhouse gas upcycling in the UK, and globally, to yield economic and social impact as well as, crucially, mitigating climate change.
For far too long we have relied on petrochemicals to provide us with the fuels and chemicals we rely on to sustain our modern lives. There are alternatives. One is to use greenhouse gases emitted by industry, (and ultimately to use GHG captured from the atmosphere) in gas fermentation processes, exploiting biological systems (bacteria) to make the chemical building blocks we need for sustainable plastics, fine chemicals and fuels.
The Synthetic Biology Research Centre (SBRC) at the University of Nottingham is arguably the best-equipped UK academic facility capable of doing this. Our research uses engineering biology approaches to understand and then modify industrially-relevant bacteria. The bacteria in our gas fermentation systems use carbon dioxide (CO2) as the building block to make larger organic molecules which could be sustainable jet fuel, biodegradable plastics, or chemical building blocks for the chemicals industries which currently rely on petrochemical feedstocks. Our primary focus is not on making fuels which would be burnt (releasing CO2), but on the production of chemicals which lock up carbon for longer periods of time.
Gas fermentation itself is not new; it is a well-known natural biological process. Interest in it is, however, having a renaissance driven by the need for climate mitigation. What is new here is our ability, driven in the UK by the SBRC, to engineer bacteria to more efficiently and effectively convert GHGs into the everyday chemicals society needs. In addition, the SBRC houses The Carbon Recycling Network, one of 6 Networks in Industrial Biotechnology & Bioenergy funded by the UKRI-BBSRC (BBSRC-NIBB) to encourage the growth of Industrial Biotechnology in the UK. The Network has over 500 members globally from a range of sectors including world leading academia, industry, research funding and research and technology organisations.
The SBRC has created and uses advanced genome engineering tools to modify existing bacteria into mini factories which manufacture the specific chemicals we need. Its science is world-leading, and it is linked with a wide range of companies which are once more taking gas fermentation from academic lab research to industrial application.
One such commercial pioneer is LanzaTech, which is already producing ethanol at industrial scale from industrial waste gases. It has already powered a Virgin Atlantic jet with its sustainable aviation fuel. Although LanzaTech is not yet applying synthetic biology commercially to make other chemicals, we have worked with LanzaTech on such projects and plan to do so again. Also of particular note are the two start-up companies which have emerged from the SBRC’s core research area. Deep Branch is an agile new company founded by three former SBRC PhD students, which is pioneering the production of sustainable animal feed from waste CO2 gas. In just three years it has grown from concept to a company that has raised well over €8m to build a pilot plant for FishKind single-celled protein. PhaseBio Labs is an even newer company with a focus on converting industrial waste CO2 into chemicals, reusing all the CO2 and preventing GHG emissions.
"Microbial gas fermentation will be a key part of sustainable economies and provides a solution for keeping industrial gases out of the atmosphere as well as for municipal solid waste recycling."
Despite these industrial advances, discussions with BEIS suggest that the government is not fully aware of the potential for gas fermentation. Microbial gas fermentation will be a key part of sustainable economies and provides a solution for keeping industrial gases out of the atmosphere as well as for municipal solid waste recycling. It is important to add that gas fermentation has a minimal footprint and does not compete with agricultural land. Showcasing the potential of gas fermentation to policymakers and influential government officials will sharpen their focus on a technology area which is “oven-ready” for at least one biofuel product, and which has a great deal more to offer in terms of the products it can make – which is what SBRC and Carbon Recycling Network are working on. It is therefore crucial to build policy engagement capacity for research centres and ensure that these issues are prominent on the political agenda.
Nigel Minton
Professor Nigel Minton is Director of the UKRI-BBSRC/EPSRC Synthetic Biology Research Centre – Nottingham (SBRC).