In-situ production of microbial protein with reclaimed ammonium in a microbial electrochemical recovery conversion cell

Description

Microbial protein (MP) is regarded as a promising alternative to plant/animal based protein to feed the world because of its low environmental impact. In-situ and cost-effectively recovery of nitrogen from wastewater is one of the key challenges to economy of MP production. We therefore proposed a two-chamber microbial electrochemical recovery conversion cell to meet the challenge. A representative MP producer, Cupriavidus necator, could fix carbon dioxide as protein-rich biomass in the cathode chamber with ammonium recovered from wastewater in the anode chamber through diffusion and electroosmosis and in-situ generated hydrogen and oxygen through water electrolysis. MP was successfully obtained with an external power supply of 3 ~ 5 volt and the MP yield was 0.81 g/L in 36 h at 5V in batch mode. C. necator could grow in cathode even when the anode chamber was filled with ammonium solution in a broad range (0.05 ~ 8 g N/L). Highest MP yield 0.9 g/L was achieved in 36 h at 2 g N/L. The system was also proved had the ability to produce MP with reclaimed ammonium from real wastewater streams (e.g., influent from municipal wastewater and digestate) and the protein yielded had a high quality on amino acid profile.

Period	12 Sept 2021 → 15 Sept 2021
Event title	5th European Meeting of the International Society for Microbial Electrochemistry and Technology
Event type	Conference
Conference number	5
Location	Girona, SpainShow on map
Degree of Recognition	International