Novel Biological Approach to Mitigate Methane Emissions from Livestock Slurry through Microbial Conversion of Glycerol

Pig farming is a major contributor to the emissions of greenhouse gases and pollutants. Methane (CH₄), with a global warming potential 27 times that of carbon dioxide (CO₂), accounts for up to 80% of the greenhouse gases at the farm level. Concurrently, pig production is responsible for 15% of the global livestock-related ammonia (NH₃) emissions. Mitigation strategies that are highly effective and environmentally friendly are lacking. Here, we present a novel slurry treatment driven by the biological conversion of glycerol by <i>Limosilactobacillus reuteri</i> with the support of indigenous slurry microbiota activity, leading to the formation of the reuterin system, a broad-spectrum antimicrobial. The <i>in situ</i> production of reuterin reduced CH₄ emissions by up to 95% in pig slurries and lowered CO₂ and NH₃ emissions, depending on the slurry type. Taken together, the microbial conversion of glycerol by <i>L. reuteri</i> holds promise as a biological slurry treatment to mitigate agriculture-related greenhouse and pollutant gas formation.