Meat versus microbial protein‒a life cycle assessment of present-day value chains

Replacing meat-based protein with more sustainable options is a pivotal strategy towards the fulfillment of the United Nations Sustainable Development Goals. An ever-increasing global demand for protein-rich nutrition has to be satisfied. This study conducts a comparative life cycle assessment of two contemporary value chains—pork meat and bioreactor-based microbial protein—to evaluate their environmental impact. Pork meat production is examined based on primary data from German manufacturers, including two consecutive pig production facilities and one slaughterhouse. Microbial protein production is based on literature data covering a commercialized process and estimates are derived from process simulations. Both production processes are assessed for their impact on global warming, land use, water use, and non-renewable energy demand based on 1 kg protein output as functional unit. The results indicate that microbial protein production offers reductions in land and water use by 94% and 70%, respectively. In addition, microbial protein production shows slightly higher impacts for global warming and a three-fold increase in non-renewable energy demand, mostly resulting from the glucose syrup feedstock and energy for medium sterilization. Furthermore, the global warming impact of pork production benefits from offsets through biogas credits. A Monte Carlo simulation provides uncertainty estimators for both production chains which shows, in particular, that it is not possible to draw conclusive statements about the impact on global warming. Microbial protein demonstrates significant reductions in land and water use compared to pork, indicating strong potential for improved sustainability. However, its overall advantage depends on reducing energy demand and sourcing low-impact carbon feedstocks, which are critical prerequisites for achieving a truly sustainable profile.