A new project aims at developing a technology for extracting protein from organic waste, which can subsequently be used as a protein supplement for humans or in animal feed.
Copenhagen/Denmark — A new project based on circular economy examines the possibility of utilizing biowaste from Copenhageners to produce single-cell proteins, which can be used as a protein supplement for humans or be included in animal feed for cattle, pigs, poultry, fish, etc., as a substitute for the climate-damaging alternatives such as fish meal and soya beans used today.
The project is run by a team of researchers at DTU Environment. Their idea is to combine existing technology already being used for biogas production with new technology based on the gases and wastewater resulting from biogas production. The project will use biogas produced from organic waste from Copenhagen households, but in principle it may equally be biogas produced from wastewater or organic industrial waste.
Methane is separated during the production of biogas. In the project, methane is used as a growth agent for microorganisms known as methylotrophs. These microorganisms have an excellent protein composition, and are approved by the EU as a protein supplement for humans as well as for use in animal feed. In addition to methane, nutrients like nitrogen and phosphorous are also used in the cultivation process for mehtylotrophic bacteria. Both are found in abundant quantities in biogas production wastewater.
Both methane and the extracted biogas production nutrients are placed in a reactor in which the methylotrophic bacteria produce single-cell proteins. The proteins can then be harvested from the reactor, freeze-dried, and used as a protein supplement or in animal feed as a substitute for the fish meal or soya beans which currently constitute the protein source.
A pilot demonstration of the methods will be constructed at the Avedøre Wastewater Treatment Plant in collaboration with Unibio, Envidan, and Biofos. The project is supported by the Ministry of Environment and Food of Denmark and has a duration of 18 months.