Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Even bacteria need their space: Squished cells may shut down photosynthesis

24.03.2020

Introverts take heart: When cells, like some people, get too squished, they can go into defense mode, even shutting down photosynthesis.

In a study published today, a team at the University of Colorado Boulder took advantage of a new microscopic technique to follow the lives of individual bacteria as they grew and divided in complex colonies.


The cyanobacteria cells near the inside of this colony fluoresce more than those at its edges.

Credit: Kristin A. Moore and Jeffrey C. Cameron

The researchers discovered something unexpected in the process: Whenever these single-celled organisms, a type of cyanobacteria or blue-green algae, got too smushed, they began to switch off the machinery that was essential for them to turn sunlight into sugar.

The tiny organisms, in other words, slowed down their growth in a big way, said Jeffrey Cameron, an assistant professor in the Department of Biochemistry and coauthor of the new research.

"If a cell is between a rock and a hard place, internally everything says, 'Yes, I have nutrients. I want to grow,'" said Cameron, also of the Renewable and Sustainable Energy Institute (RASEI) at CU Boulder. "But there also has to be a feedback that says, 'I need to turn off photosynthesis so I don't expand and rupture.'"

The findings, which appear in Nature Microbiology, provide a new window on this process that sustains most life on Earth--and, in particular, how organisms regulate photosynthesis when the going gets tough. Cameron hopes that his team's results will also help scientists to develop custom-made microbes that could one day turn light into electricity or even construct living buildings.

Bacterial pancakes

As Cameron explains, it all began almost by accident.

He launched this research several years ago with a deceptively simple goal in mind: He and his colleagues wanted to track the behavior of individual cells within a bacterial colony throughout their entire lifecycle.

That was a difficult feat--for simple-looking organisms, cyanobacteria can form pretty complex structures.

"The cells on the outside of a colony are exposed to a lot of light, while those on the inside have low light exposure," Cameron said. "Over time as they grow and accumulate more cells, they shade themselves."

To be able to see every single cell in a growing colony, Cameron developed a method of culturing cyanobacteria so that they spread out like flat pancakes. When he started peering at these two-dimensional growths under a microscope, he noticed something odd: The more the colonies grew, and the more the bacteria inside began to squeeze together, the more they began to glow, or "fluoresce," under a certain type of light.

The microbes, he explained, were emanating heat out to their environment, almost like a person perspiring on a packed city bus.

"I dropped everything and spent the next four years figuring out what was happening," Cameron said.

The key, he and his colleagues discovered, was that the cells in a colony weren't all glowing the same. The cyanobacteria on the inside of a colony, for example, fluoresced a lot more than those on the fringes. They also grew a lot slower, dividing in two at about half the rate as their exterior cousins.

Put differently, when cells get squished, they shine.

"When the cells become confined, and they can't expand, they become highly fluorescent," Cameron said.

Tiny antennae

So why were those interior cells perspiring so much?

To answer that question, you have to get to know the phycobilisome. This teeny, protein-based structure is the antenna of the cell. Many of these phycobilisomes sit inside cyanobacteria where they collect sunlight, then transport it to the reaction sites where that energy can be converted into glucose, or sugar.

Or that's what usually happens. Cameron and his colleagues found that when their cyanobacteria became too confined, they started to shed their phycobilisomes.

"If the cyanobacteria got more light than they could use for photosynthesis, these antennae would literally pop off," Cameron said.

The microbes couldn't use all that energy, so to keep from getting glutted, they turned off photosynthesis.

The group's results, he said, show just how dynamic single-celled organisms can be: They have a lot of tools for staying healthy in a dynamic social environment.

Understanding that social environment could also one day help scientists put photosynthesis to work--tapping sunlight to design more sustainable buildings or make other biology-based tools.

"We might be able to develop small-scale machines that are using light to perform computations or work," Cameron said.

It's a whole new way to think about catching some rays.

###

Other coauthors on the new study include CU Boulder researchers Kristin Moore, a former graduate student in RASEI; Sabina Altus, a graduate student in the Department of Applied Mathematics; Jian Wei Tay, an image analysis specialist in RASEI; Janet Meehl, a professional research assistant in RASEI; Evan Johnson, lab manager; and David Bortz, an associate professor in applied mathematics.

Daniel Strain | EurekAlert!
Further information:
https://www.colorado.edu/today/2020/03/23/cyanobacteria-photosynthesis
http://dx.doi.org/10.1038/s41564-020-0684-2

More articles from Life Sciences:

nachricht Why developing nerve cells can take a wrong turn
04.06.2020 | Universität zu Köln

nachricht Innocent and highly oxidizing
04.06.2020 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Small Protein, Big Impact

In meningococci, the RNA-binding protein ProQ plays a major role. Together with RNA molecules, it regulates processes that are important for pathogenic properties of the bacteria.

Meningococci are bacteria that can cause life-threatening meningitis and sepsis. These pathogens use a small protein with a large impact: The RNA-binding...

Im Focus: K-State study reveals asymmetry in spin directions of galaxies

Research also suggests the early universe could have been spinning

An analysis of more than 200,000 spiral galaxies has revealed unexpected links between spin directions of galaxies, and the structure formed by these links...

Im Focus: New measurement exacerbates old problem

Two prominent X-ray emission lines of highly charged iron have puzzled astrophysicists for decades: their measured and calculated brightness ratios always disagree. This hinders good determinations of plasma temperatures and densities. New, careful high-precision measurements, together with top-level calculations now exclude all hitherto proposed explanations for this discrepancy, and thus deepen the problem.

Hot astrophysical plasmas fill the intergalactic space, and brightly shine in stellar coronae, active galactic nuclei, and supernova remnants. They contain...

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Why developing nerve cells can take a wrong turn

04.06.2020 | Life Sciences

The broken mirror: Can parity violation in molecules finally be measured?

04.06.2020 | Physics and Astronomy

Innocent and highly oxidizing

04.06.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>