Biological Ammonia Production via Anaerobic Fermentation of Soy Meal Protein

Abstract

Background: Conventional ammonia production methods, notably the energy-intensive Haber–Bosch process, are costly and contribute substantially to about 2% of the world’s CO2 emissions. This study focuses on the biological approach to convert protein to ammonia via hyper-ammonia-producing bacteria (HAB) fermentation. Methods: A consortium of ruminal microbes was employed in this work to ferment soybean meal protein under varying processing conditions. The parameters investigated included pH (7–11), inoculum concentrations (1–10%), substrate concentrations (5–20%), and fermentation time (0–168 h). Results: Optimal conditions for microbial growth and biological ammonia production were observed at pH 7, fermentation duration of 72 h, inoculum concentration of 10%, and substrate concentration of 10%. ~8000 mg/L biological ammonia was produced following HAB fermentation. Conclusions: By leveraging the capabilities of rumen HAB, this study contributes to the ongoing efforts to develop environmentally friendly processes for ammonia production that will mitigate both economic and environmental concerns associated with traditional methods.

Keywords

• soy meal protein isolate (smpi)
• fermentation
• ph
• alkalinity
• biological ammonia
• hyper-ammonia-producing bacteria