Controlling ruminant methane emissions employing lactic acid bacteria and their metabolites

PI: Hilario Mantovani

Mantovani is an assistant professor of animal and dairy sciences who specializes in rumen microbial physiology at UW–Madison. His research program is focused on understanding the functions and ecological interactions between anaerobic microbes that colonize the gastrointestinal tract of ruminants. Mantovani’s position is funded by the Dairy Innovation Hub.

Graduate student (pictured above): Alice Helena Peres Marques Assumpção is pursuing a PhD in animal and dairy sciences and is mentored by Hilario Mantovani. She earned her master’s in animal productivity and quality from University of Sao Paulo in Brazil. Her Her research project evaluated nutritional strategies to mitigate the methane emission on beef cattle production, through evaluation of the parameters and products of enteric fermentation and the rumen microbiota.

Lactic acid bacteria (LAB) are natural colonizers of the gastrointestinal tract of young livestock. Several LAB produce antimicrobial peptides (AMPs) and previous research indicated that LAB metabolites can reduce methane production by mixed cultures of rumen microbes. These effects on ruminal methanogenesis may be due to metabolic shifts in the fermentation, reduced availability of substrates (e.g. electron donors) for methanogenesis, or direct inhibition of methanogenic archaea. However, our understanding of how LAB strains inhibit rumen methanogenesis is very limited. We hypothesize that rumen methanogenic archaea are susceptible to AMPs produced by LAB from shared ecological niches and the overall objective of this proposal is to screen ruminant microbiomes for AMP-producing LAB that inhibit methanogenic archaea. We will employ high-throughput screening of LAB strains and viable candidates will be subjected to whole-genome sequencing to expedite the identification of biosynthetic gene clusters potentially encoding AMPs. The predicted peptides will be purified and characterized and evaluated for effectiveness to reduce methane production and modulation of rumen fermentation in vitro. This research supports the Wisconsin Dairy Task Force 2.0 Recommendation #4: “Need for a consistent industry message” and also aligns with Recommendation #47: “Need for regulatory certainty and consistency”

Alice Marques