SEP 27, 2018 1:02 PM PDT

How Bacterial Cells Take out the Trash

WRITTEN BY: Carmen Leitch

Some types of bacteria create tiny versions of themselves that cannot reproduce - miniature spheres lacking chromosomal DNA that are known as minicells. They can be up one-fifth of the size of a microbe, but it was not known why bacteria would make these structures, until now. Researchers at the University of California San Diego found that these minicells are used by bacteria to dispose of unnecessary material, which is a critical process for the cell's survival. Their findings have been reported in the journal mSphere.

These are bacteria discard damaged proteins inside a fluorescent green-labeled minicell. / Credit: Chao Lab, UC San Diego

"It's amazing that even bacteria take out their garbage," said the first author of the report, Camilla Rang, a research specialist in Professor Lin Chao's laboratory in the Division of Biological Sciences. "We have shown that minicells can be beneficial for the bacteria and help them escape death by kicking out the damaged proteins."

Minicells protrude from microbial cells, and the Escherichia coli bacterium uses them to bundle damaged proteins that are collected from inside the bacterial cell. 

To learn more about how the minicells are connected to bacterial cell health, the scientists used fluorescent tags to highlight and visualize proteins as they moved through the E. coli cell. When the bacterium was exposed to an antibiotic, streptomycin, the researchers were able to track damaged proteins as they moved to the ends of the cell, were packed into a minicell and moved out of the microbe.

These time-lapse images illustrate E. coli ejecting a fluorescent green-colored minicell. / Credit: Chao Lab, UC San Diego

These minicells, suggested the researchers, may enable bacteria to survive or persist when they are challenged by antibiotics. 

There has been significant research interest in minicells because they have a lot of potential as a drug delivery system that can be targeted to certain places. Such strategies are often employed in cancer therapeutics, which work more efficiently when they target only cancerous cells. They can be used to send treatments exactly where they’re needed. 

In the video above from the Chao lab, cells that use the minicell system are able to survive when exposed to an antibiotic, while cells lacking minicells don't make it.


Sources: AAAS/Eurekalert! via UCSD, mSphere

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
DEC 02, 2019
Microbiology
DEC 02, 2019
Understanding How a Superbug Spreads in the Home
Superbugs, which are pathogens that are resistant to the effects of antibiotics, are a rising threat to human health....
DEC 05, 2019
Drug Discovery & Development
DEC 05, 2019
New Injection that Treats Peanut Allergy
Peanut allergies affect between 1 and 3% of the US population. Associated with a heightened risk of severe anaphylactic reactions, oral immunotherapy is th...
DEC 09, 2019
Genetics & Genomics
DEC 09, 2019
Researchers Rewire E. coli to Consume Carbon Dioxide
Milo et. al.   Researchers have genetically rewired the metabolism of Escherichia coli to be autotrophic, using formate (COOH) as a food sou...
DEC 23, 2019
Microbiology
DEC 23, 2019
Snow-Loving Algae Thrive at the Heights of the Andes
The Andes Mountain range runs along the edge of western South America. Microbial life has found a home high in those mountains....
JAN 06, 2020
Drug Discovery & Development
JAN 06, 2020
Designing Drugs To Fight off C. Diff Infections
A study published by PNAS explains breakthrough research around designing drugs that target C. diff bacterial infections that result in 15,000 deaths in th...
FEB 14, 2020
Microbiology
FEB 14, 2020
CDC Director Expects Coronavirus to Find a "Foothold"
The novel coronavirus that emerged in Wuhan, Hubei Province, China has now infected over 64,000 people....
Loading Comments...