Evaluation of Clostridium Co-Culture Fermentations with Sustainable Feedstocks
Feasibility Funding helps Celtic Renewables de-risk avenue of investigation and acquire data for further research.
Introduction
Celtic Renewables’ patented low-carbon technology converts co-products from the whisky industry into high-value chemicals, sustainable biofuel, and other commercially and environmentally valuable products. One of the products they make is solvents. This project sought to investigate whether they could improve their process for producing solvents, from whisky co-products and waste potatoes, by expanding the range of bacteria they use to break down and transform those ‘feedstocks’. This project investigated the use of combinations of Clostridium (co-cultures) to increase yield.
Challenge
Celtic Renewables process uses a combination of feedstocks which are quite different in nature. Often it can be difficult to find one strain which can utilise different feedstocks as maximally as each other. Being able to maximise the use of all the feedstocks would also deliver large benefits for the company. Even a small increase in yield would be extremely beneficial.
Celtic Renewables process was developed using clostridia bacteria to convert whisky co-products and rejected potatoes into solvents. The company wanted to know if co-cultures could improve their output.
Solution
IBioIC awarded Feasibility funding to Edinburgh Napier University to work with Celtic Renewables on this challenge.
The team at Edinburgh Napier University tested combinations of Clostridium co-cultures to see if solvent yields could be improved.
Two strains were purchased from National Collections of Industrial, Food and Marine Bacteria (NCIMB). These were combined with multiple strains used in the CRL process.
In lab medium, co-culture with one CRL strain resulted in increased production of ethanol, butanol and acetone.
Although enhancement in solvent production was not observed, there was improvement in yield with most of the co-culture fermentations on CRL medium.
Outcome
There was some indication of benefits derived from using co-cultures on lab-based media, but little to suggest a benefit on Celtic Renewables’ medium. While this needs to be studied further, the project has helped de-risk an avenue of work which Celtic Renewables could pursue in future by providing pilot data for further grant applications.
“This project allowed valuable research to be undertaken which the company would have not been able to have normally found resource for. The IBioIC has allowed us to continue our much valued industrial-academic relationships, derisking and allowing the company to explore new avenues. ”
Gram Stain of one of the co-cultures