Yeast cells cause embedded objects to rise via the microbial Brazil nut effect

Microbial Brazil nut effect artwork
Credit: Srivastava et al.

A phenomenon where microbe-generated gas bubbles create granular fluctuations at the wet sandy floors of rivers, oceans, and lakes has revealed more about the distribution of materials at the bottom of waterbodies.

Tohoku University Researchers dubbed this the “microbial Brazil nut effect.” Details of their research were published in the journal Soft Matter on October 6, 2021.

The Brazil Nut Effect (BNE) happens when a granular mixture subjected to shaking results in bigger particles ending up on top. The name stems from a typical container of mixed nuts, where the larger Brazil nuts inhabit the surface and smaller nuts fall below. BNE has wide-ranging scientific applications, from boulder placement on asteroid surfaces to the pattern formation in early mammalian embryos.

The team set out to test the effects of plastic waste on the ecosystem by mixing silicon rubber into a yeast fermentation vessel. Some microorganisms use cilia and flagella to swim in water. Yeast does not. It rises to the surface at a speed of several centimeters per second by attaching itself to the bubbles it produces during the fermentation process.

Based on the team’s experiments, the artificial material moved up and down from the floor of the vessel to the top, agitating the contents. As a result, nutrients were spread throughout the vessel, promoting further growth of yeast.

The researchers also discovered that microbial fermentation-induced moving transported buried materials one billion times larger than the microorganism itself.

“We successfully visualized and measured the physical phenomenon of soil fluidization and the emergence of buried objects to the water surface due to particle submergence in environments where soil is deposited, such as lake bottoms, river bottoms, and seabeds,” said Kenji Kikuchi, co-author of the study.

The discovery is expected to contribute to the reemergence of dormant microorganisms and viruses in the soil and further our understanding of how unknown pathogens surface.

Journal: Soft Matter
DOI: 10.1039/D1SM01327K
Article Title: Microbial Brazil nut effect
Article Publication Date: 6-Oct-2021

Media Contact

Public Relations
Tohoku University

Media Contact

Public Relations
Tohoku University

All latest news from the category: Earth Sciences

Earth Sciences (also referred to as Geosciences), which deals with basic issues surrounding our planet, plays a vital role in the area of energy and raw materials supply.

Earth Sciences comprises subjects such as geology, geography, geological informatics, paleontology, mineralogy, petrography, crystallography, geophysics, geodesy, glaciology, cartography, photogrammetry, meteorology and seismology, early-warning systems, earthquake research and polar research.

Back to home

Comments (0)

Write a comment

Newest articles

New, highly efficient catalyst for propylene production

Researchers have developed an innovative catalyst for the synthesis of propylene, which has potential benefits for the chemical industry and carbon recycling. Propylene is a colourless, flammable hydrocarbon gas that…

Revolutionize satellite power using laser beaming

The University of Surrey and Space Power are tackling the problem of powering satellites in Low Earth Orbit (LEO) during their eclipse period when they cannot see the sun. By…

Researchers identify proteins that could predict liver transplant rejection

Finding could help physicians catch rejection earlier and modify immunosuppression. Northwestern University scientist have discovered families of proteins in the body that could potentially predict which patients may reject a…

Partners & Sponsors