DEC 14, 2016 04:59 PM PST

Soil Fungal Network Improves Gene Transfer Among Bacteria

WRITTEN BY: Carmen Leitch

Soil is rich with microbial life, as it provides an environment with myriad microhabitats that can provide sustenance, as long as the microbes adapt to fluctuating environmental conditions. Within a colony of microbes, it’s important for them to utilize a common mechanism called horizontal gene transfer (HGT) in order be adaptable; close contact between microbes is required for HGT to work. In soil, it’s not easy for bacteria to get around. New work in Scientific Reports has shown that fungi provide a liquid film, a layer of mucous called fungal hyphae, which eases that process in the challenging soil environment. In addition, a network of fungus, a mycelium, sets up an infrastructure that the hyphae envelopes. There can be hundreds of meters of mycelium in only one gram of soil. 

Micrograph visualising the distribution of transconjugant bacteria (in green) along a hyphal network (in white). Transconjugant bacteria are formed by direct contact and horizontal gene transfer of differing bacteria (in red and black) invading the hyphae from the right and the left side, respectively. /Credit: Berthold et al. 2016 in Scientific Reports

"In the fine liquid film surrounding the hyphae, bacteria can move with much greater speed and direction and cover more distance than in soil water without hyphae," explained the first author of the study, Tom Berthold, a doctoral researcher at the UFZ Department of Environmental Microbiology. "For bacteria, fungal hyphae are like a motorway which gives them fast, direct access to their food sources."

Bacteria meet up on the fungal network, and exchange genetic material with one another when they do. "It's similar to the transmission of cold germs on a packed train," explained environmental microbiologist Dr. Lukas Y. Wick. "But unlike a cold, the new genes are usually an asset to the soil bacteria. They enable them to adapt better to different environmental conditions."

The genes that are shared on the fungal network can help microbes use a new kind of food source, or enable it to withstand exposure to a pollutant, in some cases even consuming the chemical. Some bacteria, for example, can use benzene or toluene, ingredients in stuff like paint and gasoline, as food. Sharing that ability is of course very beneficial to a population. The video below shows the Pseudomonas bacterium moving along hyphae.

 

In this work the researchers show that HGT occurs far more when it happens between bacteria on a fungal network than in a place without hyphae. Computer models agreed with their findings. "Our study shows that fungal hyphae not only provide soil bacteria with an excellent infrastructure, but also a potential hot spot for bacterial horizontal gene transfer. This previously unknown aspect of fungus-bacteria interaction is an important step towards understanding the complex interactions between soil-dwelling microorganisms," said Wick.

It seems that fungi thus play a vital role in the soil habitat. "Just a few years ago, we were still completely unaware of this. It's possible that over the course of the Earth's history, bacterial diversity increased massively with the development of mycelium-forming fungi," concluded Wick.

 

Sources: AAAS/Eurekalert! via UFZ Helmholtz Centre for Environmental Research, Scientific Reports

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
NOV 16, 2019
Earth & The Environment
NOV 16, 2019
What role does a light-capturing marine microbe play in climate regulation?
A USC-led research team discovered the unique role that a light-capturing marine microbe plays in regulating Earth’s climate. The team consisted of s...
NOV 16, 2019
Cardiology
NOV 16, 2019
Stem Cells Improve Post Infarction Repair
Following a heart attack, tissues within the heart are often damaged. Once damaged, the heart is incapable of regeneration of these tissues. These dead are...
NOV 16, 2019
Microbiology
NOV 16, 2019
Colombia Declares a State of Emergency as Banana Fungus Reaches the Americas
Bananas: the world's most popular fruit, a major source of food for millions of people, and now, seriously threatened by fungus....
NOV 16, 2019
Microbiology
NOV 16, 2019
Cataloging the Microbial Genes in the Human Microbiome
The human body carries a large community of microbes, and the ones living in our gastrointestinal tract exert a powerful influence on our biology....
NOV 16, 2019
Microbiology
NOV 16, 2019
Large Study Shows That Birth Mode Impacts Infant Microbiome
The microbiome is impacted by mode of birth - babies born by Cesarean section have a different microbiome than babies born vaginally....
NOV 16, 2019
Drug Discovery & Development
NOV 16, 2019
New Potential Early Stage Treatment for Parkinson's
Parkinson’s Disease is the second most common neurodegenerative condition, affecting 35 million people globally. Currently without a cure, researcher...
Loading Comments...