A life cycle assessment of microbial protein production

This study assessed the environmental impacts of microbial protein (MP) produced by autotrophic hydrogen-oxidizing bacteria. An attributional life cycle assessment (LCA) with a cradle-to-gate approach was used to quantify global warming potential (GWP), land use, freshwater and marine eutrophication potential, water scarcity, water degradation, and the cumulative energy demand (CED) of MP production in Finland. Two scenarios were assessed using different electricity sources and results were compared with animal- and plant-based protein sources. The results showed that electricity consumption had the highest contribution to environmental impacts. MP production using hydropower as an energy source yielded 94% lower GWP compared to using the average Finnish electricity mix. In comparison with animal-based protein sources, MP had 59-100% lower environmental impacts depending on the reference product and the source of energy assumed for MP production. When compared with plant-based protein sources, MP had lower land and water use requirements but GWP was reduced only if low-emission energy sources were used.