Circularising the bioeconomy

Circular economy
Sustainability
 
21 Oct 2021

Food and drink manufacturing waste and by-products have the potential to power a circularised bioeconomy, whilst also relieving tensions in the food-versus-fuel debate and supporting efforts to achieve targets in climate change, sustainability and food security, argues Professor Louise Horsfall.

This article was first published by the Microbiology Society in A Sustainable Future - Transitioning to a Circular Economy: Opportunities and Challenges for Microbiology Research and Innovation (17 December 2020). Louise Horsfall, Professor of Sustainable Biotechnology at The University of Edinburgh, writes:

Covid-19 has had a severe impact on the economy, with public debt now larger than the size of the UK’s economy. However, it has also provided us with a massive opportunity to effect real environmental change. Developing a circular economy would lead to a 48% reduction in carbon dioxide emissions by 2030 and provide a host of opportunities for the expanding bioeconomy. The food and drink production industry is vital to the UK economy but creates unavoidable bio-based waste that largely goes to landfill, resulting in methane gas production, causing environmental pollution and contributing to climate change. Food and drink manufacturing waste and by-products therefore constitute a vast resource that is currently underutilised. They have the potential to power a circularised bioeconomy, whilst also relieving tensions in the food-versus-fuel debate and supporting efforts to achieve targets in climate change, sustainability and food security.

The circular economy model may be bioinspired, but the biological cycles and cascades are somewhat underdeveloped and oversimplified. What is needed is a multidisciplinary research approach that incorporates new technologies able to utilise the waste and by-products of food and drink production to their full potential. Three areas of technical development could improve resource flow and circularity within a bioeconomy powered by waste from the food and drink sector:

  1. Separation of valuable by-products, e.g. the removal of proteins for animal feed.
  2. Biological transformation of by-products into new products, with concomitant redesign of biological systems and processes to minimise waste, e.g. the production of high yields of enzymes using microbes engineered for increased lifespan to reduce washing, sterilisation and waste.
  3. Conversion of biomass, including that resulting from biological processes, into carbon products and chemicals through thermochemical processing or anaerobic digestion – thereby providing an alternative route, by which even the treated biomass of genetically modified micro-organisms could be used to regenerate natural systems through thermochemical conversion to useful soil additives.
The interdisciplinary challenge of circularising the bioeconomy is clearly enormous and expertise in the field of microbiology is key to overcoming it.

There are specific challenges associated with using complex industrial by-products and wastes as feedstocks, instead of comparatively pure commercial growth media for microbial growth. Impurities that can accumulate in the growth medium to inhibitory or toxic levels, as well as unfavourable consequences of harsh raw material pre-treatment conditions, such as very low pH, represent chemical stresses for the microbial production strains. Whether it be a source of new genes or as alternative ‘chassis’, we will be reliant on a diverse range of micro-organisms to adapt the current microbial production platforms to better tolerate unfavourable conditions and impurities. New bio-based products will be produced from food waste by moving away from our ‘go to’ hosts, Escherichia coli and Saccharomyces cerevisiae, and diversifying the pallet of tools available to biotechnology.

As climate change imposes further stresses on land use, food security will depend on our ability to control our own supply chains. The UK currently imports 50% of its food and feed. A circular bioeconomy would reduce our demand for imports, lowering carbon footprints and environmental pollution. Valorisation of waste is critical to the maintenance of our limited arable land and marine resources, while still protecting the UK’s natural environment.

Header image courtesy: Unsplash

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