Project

Producing volatile fatty acids and/or organic acids from waste: rumen as a bioreactor.

The human population and energy use are non-stop increasing day by day. In terms of environmental and energy management, these issues will also drive up tons of waste from human life and may lead to a fast depletion of fossil energy sources. Approximately 40% of food in U.S. and Europe is discarded as waste and it is difficult to efficiently treat. On the other hand, biomass and waste are interesting to produce novel or renewable energy. Providing the alternative energy and solving waste management costs at the same time, is an attractive sustainable solution.

Volatile fatty acids (VFAs) and/or organic acids (OAs), such as acetate, propionate butyrate, lactate, valerate and succinate, can be used as the building-blocks for chemicals and biofuels. At present, volatile fatty acids are produced from petroleum and natural gas. VFAs/OAs alternatively can  be produced from anaerobic microbial digestion of waste.

Figure: schematic illustration of alternative energy production from waste by using the rumen of a cow as "bioreactor".
Figure: schematic illustration of alternative energy production from waste by using the rumen of a cow as "bioreactor".

Rumen, the first large stomach of ruminant animals, is a powerful living anaerobic “bioreactor” that is not only a fruitful source of microbial biodiversity but also contains sources of enzymatic activities that are still undiscovered. Rumen microorganisms, which are around 10 to 50 billion bacteria, 1 million protozoa and variable numbers of yeasts and fungi (Chiba 2009), can convert various compounds such as carbohydrate, protein and fat into VFAs/OAs under anaerobic conditions. This is an attractive source to turn waste into valuable compounds. Therefore, this research aim is to produce VFAs/OAs from waste such as starch waste by using rumen fluid as an inoculum. Microbial diversity and novel bacterial species that are involved in VFAs/OAs production are also in this interest.

Overall, the purpose of this research will be to study

1) The production of resources from waste

2) Optimize conditions of VFAs/OAs fermentation process under anaerobic condition in lab-scale.

3) Rumen microbial diversity and its interaction in anaerobic digestion (hydrolysis and acidogenesis steps)

4) Isolation and identification of microorganisms as well as a novel species that are producing the resource.

This research is support by Royal Thailand government scholarship and performed in cooperation between Wageningen University and Thailand institute of scientific and technological research.