From waste to renewable chemicals: Steering microbes for enhanced VFA production and beyond

About the Project

Transitioning to a bio-based circular economy is essential for the conversion of organic feedstocks into bioenergy and biomaterials. Anaerobic digestion (AD) is central to this transformation, achieving up to 90% valorisation efficiency while producing volatile fatty acids (VFAs)—acetate, propionate, and butyrate—that can be used as raw material to produce bioplastics, food packaging and green chemicals.

Agricultural feedstocks—including livestock manure, crop residues, and food-processing byproducts—represents a substantial global resource, with more than 5.5 billion tonnes generated every year worldwide. In the UK, however, agricultural residues remain largely underutilised. England alone generates around 29 million tonnes of manures and slurries each year, yet only about 5% is processed through AD. Similarly, each year, around 1.3 billion tonnes of food waste are produced globally but the application of AD to convert these into bio-based compounds and bioenergy remains limited.

Exploiting even a fraction of these resources for VFA production would reduce environmental impacts and establish a sustainable production of renewable chemicals, supporting net-zero and circular economy goals. However, increasing the VFA production efficiency is constrained by limited understanding of the complex dynamics of the microbial populations underlying VFA production in AD systems. Moreover, production of one-type VFA (i.e. propionate or butyrate) requires enhanced activity of specific microbial strains reverting the metabolic pathways towards certain VFA. This project will elucidate the key microorganisms and active metabolic pathways underpinning VFA production from agricultural and food waste as feedstocks. By linking microbial dynamics with process performance, we will develop strategies to steer communities towards predictable, optimised outcomes, enabling scalable and efficient valorisation of agricultural and food waste into high-value chemicals and bio-based compounds.

This project will elucidate the microbial diversity and metabolic pathways responsible for selective VFA production from agricultural and food waste. Through the application of a bioaugmentation strategy, we aim to enhance the yield and specificity of targeted VFAs, which can subsequently be converted into high-value bio-based chemicals. Ultimately, this work will establish a sustainable bioconversion route from agricultural and food waste to VFA and renewable chemicals.

We will use anaerobic batch reactors, analytical approaches (e.g. gas chromatography, ion chromatography) and advanced molecular methods to analyse the microbial diversity and metabolic pathways.

Funding Notes

This scholarship is for 3.5 years at UKRI rate.