Challenge

Glucose is used in many biotechnology processes as the sole carbon feedstock and as processes intensify this puts pressure on sources of glucose which are needed for food. Finding replacements or alternative sources of glucose for fermentations is an important challenge.

Solution

Funding from IBioIC’s Feasibility Fund enabled C-Source Renewables and Stephen Wallace from the University of Edinburgh to work together to assess the potential for bread and potato waste generated from food waste to be used as a viable glucose replacement for the bioproduction of three chemicals used to make valuable industrial products which are currently manufactured from diminishing fossil resources.

C-Source Renewables procured both bread waste and potato waste and processed both into carbohydrate-rich syrups.

Stephen Wallace’s group then developed a technical process for the cleanup and sterilisations of raw waste carbohydrate syrups to microbiological grade for culture media use. They used the syrups to produce two high-value industrial targets in a variety of E. coli strains. They showed the possibility of producing exopolysaccharide slimes and demonstrated growth, freeze-drying, and recovery of S. cerevisiae under a variety of conditions using waste glucose syrups in media with little to no difference in biomass accumulation compared to commercial glucose preparations.

Outcome

This was the first demonstration that bread waste can be used to synthesise these chemicals in bacteria and has established bread waste as a viable carbon source for the circular bioeconomy.

The additional validation completed within this project has expanded the market of C-Source to customers that will utilise glucose for these and other high-value targets through waste valorisation. Further funding is currently being sought to enable intensification and further optimisation of bread waste upcycling processes.

Stephen Wallace will publish a paper on the project, which enabled a PhD student to gain experience working with an industrial partner, and the university is seeking follow-on funding.