'The ones that are better adapted will survive'

Israeli scientists’ microbial research delves into bowels of cow belch prevention

Ben-Gurion University of the Negev scientists say microbial communities adapt and adjust how they use resources in discovery that may help reduce methane emissions from cows

In a new peer-reviewed study, researchers from Ben-Gurion University of the Negev say microbes may be more socially aware than previously understood.

The findings offer a new perspective on how these single-celled organisms detect one another’s presence and change their behavior to reduce conflict and enhance work productivity.

The prevailing scientific thinking is that “organisms compete all the time for resources, and the ones that are better adapted will survive,” Prof. Itzhak Mizrahi of Ben-Gurion’s Department of Life Sciences told The Times of Israel in a video call.

“But what we found is that they somehow have the capability of sensing each other and what other microbes are doing,” said Mizrahi, who supervised the research. “Then they stop doing what is very similar and start doing something else.”

Led by Dr. Sarah Moraïs and recently published in Nature Microbiology, the study can help scientists design microbial communities for use in probiotics, biotechnology, and sustainable agriculture.

A focus of Mizrahi’s lab is on reducing methane, produced by cows.

More than 20% of global methane emissions come from livestock raised for human consumption, much of it produced by microbes that reside in the cow’s stomach, which is then released into the atmosphere through burping.

In practical terms, by understanding how microbes interact with one another, scientists may eventually be able to modify the microbes inside a cow’s rumen to emit less methane and produce more milk.

Microbes as team players

All sorts of microbes live together in diverse ecosystems, including in ocean waters, soil, the human gut, and in the rumen, the largest compartment of the stomach in cows.

“In this specific study, we asked, ‘How can microbial communities coexist, and what makes them tick?’” Mizrahi said.

The researchers built small, controlled communities of rumen microorganisms, starting with each bacterial species alone to establish a baseline of its behavior and protein production.

They used metabolomics, which tracks chemical waste, along with big data analysis and high-performance microscopy to follow the bacteria’s activity.

Then they combined two species and observed how they compromised or competed when forced to share space, eventually scaling up to four-member communities, systematically adding layers of social complexity.

“Just by using pairs or three, four, or even five microbes, we can see what type of decision a microbe will make as a function of the environment,” Mizrahi said.

The research showed an “escape from competition,” said Mizrahi, using a simple analogy. “When you see someone eating a burger, you will choose to eat a pizza, so you’re not competing for resources.”

The study also showed that neighboring microbes had a stronger effect on each of the bacteria’s protein production rather than the food source itself.

“A microbe is not defined only by its genome, which represents its potential, but also by its community,” Moraïs said in a statement. “The same bacterium can behave very differently depending on who surrounds it.”

According to David Zeevi, a researcher at Weizmann Institute of Science, “Microbes silently run the world: they produce oxygen, recycle nutrients, decompose dead organic matter, and much more.”

Zeevi, who was not involved in the study, told The Times of Israel that the research shows that each species “essentially reads its ‘social’ environment and shifts its metabolism to avoid duplicating what its neighbors are already doing. More than that, it will also define how the community will behave as a whole.”

For Zeevi, the implications of the study go well beyond controlling cows’ methane emissions.

“We now understand that the presence of your counterparts will define what you will choose to do,” Mizrahi said. “This is kind of an emerging truth that can be applied to any place where there are microbial communities.”