Figure: Matthias Hess, left, and Ermias Kebreab, right, stand in front of a system that mimics a cow's rumen and allows Hess to study gas-producing microbes. Photo by Gregory Urquiaga/UC Davis

In an effort to mitigate climate change, a team of scientists from three University of California (UC) campuses are proposing to use the gene editing tool CRISPR on microbes in the cow's gut. Their vision is to deliver gene-edited microbes as oral treatments for calves that will take effect in the gut microbial systems. The calves can carry this into adulthood, which can reduce their methane emissions for the rest of their lives.

Prof. Ermias Kebreab and AProf. Matthias Hess of UC Davis, co-principal investigators of the project, will team up with Nobel Peace Prize Winner Prof. Jennifer Doudna and Prof. Jill Banfield of UC Berkeley, and Prof. Sue Lynch of UC San Francisco in a project that will use CRISPR to reduce methane emissions in livestock to promote sustainability and health. Doudna and Banfield will build a new toolkit that applies CRISPR and metagenomics to complex microbiomes. Lynch will apply the genome editing strategies to test their impact on health. Hess will test the microbial tools and develop biocontainment strategies in a lab setting, and the results will be used by Kebreab to be applied on animals in the field. Kebreab is an animal scientist known for his breakthrough studies that reduced cow methane emissions by up to 82% with seaweed feed additives.

Cattle are the top agricultural source of methane in the United States. These methane emissions are hastened by cow burps, which are caused by gas-producing microbes in the animal's gut. Engineering the gut microbes to produce less methane can limit the emissions before they are burped out, and reducing methane emissions in any way possible will have a visible impact on the climate within the next decade.

For more information, see the news release by UC Davis.