Using genome editing technology to target methane-producing microbes in the digestive systems of cattle could be a powerful tool in reducing the livestock sector’s environmental footprint, say scientists.
Researchers say converting microbes to produce acetate — a short-chain fatty acid — instead of methane will help curb emissions whilst maintaining livestock productivity.
The shift could be crucial for producers striving to meet climate goals without sacrificing herd sizes or productivity levels.
Livestock, particularly cattle, are major sources of methane emissions due to microbial fermentation that takes place in the rumen.
While previous suggestions have included reducing livestock numbers to curb emissions, researchers in Nigeria said such measures fail to address the microbial source of the problem.
In a review analysing the most promising strategies for mitigating methane emissions in ruminants, the researchers said: “Eliminating or reducing livestock production is akin to throwing the baby out with the bathwater.”
Instead, biotech solutions targeting rumen microbes are likely more effective, scalable, and timely.
By focusing on CRISPR gene-editing, which scientists to modify specific genes, the main methane-producing microbe in cattle (Methanobrevibacter ruminantium) can be edited to establish acetogenesis.
In this process hydrogen, a byproduct of fermentation in the rumen, is changed into producing acetate rather than methane.
As well as being a potential solution for livestock producers, the report’s authors said the technique could also be scaled to other methane-creating systems, such as rice paddies and wetlands.
Long-lasting solutions
Despite gene-editing’s promise in reducing methane, the scientists said some challenges remain in field applications.
Past interventions, such as dietary modifications and breeding for low-methane animals, showed only limited success, especially in grazing systems.
“While dietary changes and chemical inhibitors have shown some success, their impact is often temporary or unsustainable in grazing environments,” they wrote.
CRISPR’s genetic approach, on the other hand, could offer a long-lasting solution directly within the microbial ecosystem of the rumen.
For livestock producers, the strategy presents a potential win-win: it could enable farms to reduce greenhouse gas emissions without cutting animal numbers or sacrificing productivity, they said.
Given methane’s short atmospheric lifespan of 10-12 years, lowering methane emissions can yield quicker climate benefits compared to focusing solely on carbon dioxide reduction.
“Methane is ripe for intervention; focusing on biotechnological solutions that target rumen microbes may offer a pervasive avenue for reducing global methane emissions,” they added.
“Channeling [hydrogen] to acetogenesis can be a remedy to rumen methane production and provide a pervasive avenue for addressing global methane emission beyond the rumen ecosystem.”
