Current biorefineries are predominantly based around single feedstock sources, extensively hydrolysed using multiple unit operations. The hydrolysate is generally converted to a single product by one of a few well-characterised organisms. Here, we report on a new approach to the biorefinery, combining a rapid, microwave heated, one-step depolymerisation process, with a yeast, Metschnikowia pulcherrima which is able to metabolise an array of oligo- and monosaccharides. During the investigation it was found that the microwave hydrolysis process was able to solubilize upto 50% wheat straw biomass by weight, mainly as oligosaccharides though also containing mixtures of pentose, hexose and anhydro-sugars with concentrations of up to 2 g L-1. However, a fine balance between elevated monosaccharide yields and the production of inhibitive compounds had to be struck with optimal microwave hydrolytic conditions found to be 190 °C. Further testing utilizing several different types of lignocellulosic biomass demonstrated it was possible to attain ~65% carbon efficiency in the conversion of Laminaria saccharina to hydrolysis products. The system was scaled to 600 mL using DDGS successfully solubilizing 66% of the feedstock, producing 33 g L-1 hydrolysate. M. pulcherrima grew well on this hydrolysate in a controlled stirred tank bioreactor (2L), yielding 8.38 g L-1 yeast biomass, a yeast biomass coefficient of 0.25. This presents an exciting, feedstock agnostic, pathway to the energy efficient production of a wide variety of commercially valuable chemical products without the need for extensive pre and post processing technologies.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 665992
- Integrated technology
- Microwave hydrolysis
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Environmental Science(all)
- Strategy and Management
- Industrial and Manufacturing Engineering
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- Department of Chemical Engineering - Professor
- Reaction and Catalysis Engineering research unit (RaCE)
- Centre for Sustainable and Circular Technologies (CSCT)
- Water Innovation and Research Centre (WIRC)
- Centre for Integrated Bioprocessing Research (CIBR)
Person: Research & Teaching