Nav: Home

Novel potent antimicrobial from thermophilic bacterium

March 12, 2019

University of Groningen microbiologists and their colleagues from Lithuania have discovered a new glycocin, a small antimicrobial peptide with a sugar group attached, which is produced by a thermophilic bacterium and is stable at relatively high temperatures. They also succeeded in transferring the genes required to produce this glycocin to an E. coli bacterium. This makes it easier to produce and investigate this compound, which could potentially be used in biofuel production. These findings were published in Nature Communications on 7 March.

The rise of antibiotic resistance has spurred the search for new antimicrobials. Bacteriocins - peptide toxins produced by bacteria to inhibit growth in similar or related bacterial strains - are a possible alternative to the more traditional antibiotics. Bacteriocins would also be useful to protect high-temperature fermentations mediated by thermophilic bacteria. But this would require the use of bacteriocins that are stable at higher temperatures.

Mystery

'That is why we were interested to find that the thermophilic bacterium Aeribacillus palladius, isolated from the soil above an oil well in Lithuania, appeared to produce an antibacterial peptide,' says University of Groningen Professor of Molecular Biology, Oscar Kuipers. Thus far, purification and identification of the compound had not been successful. Therefore, Ph.D. student Arnoldas Kaunietis from Vilnius University spent almost two years in Kuipers' lab to solve the mystery. He is the first author on the new paper.

By analyzing genomic information from the Lithuanian bacteria using BAGEL4 software, developed by Anne de Jong and Auke van Heel in Kuipers' group, genes that are responsible for the production of the bacteriocin were discovered and the final gene product was named pallidocin. The BAGEL4 software searches for gene clusters with the potential ability to produce novel antimicrobials.

Sugar

The antimicrobial turned out to be a glycocin, belonging to a class of post-translationally modified peptides. This means that after its production, one or more functional groups are added to the peptide. In the case of glycocins, this functional group is a sugar. 'Only five other glycocins were known thus far,' says Kuipers.

In order to facilitate further research and engineering of this peptide, the genes responsible for the production of pallidocin were transferred to E. coli BL21 (DE3) bacteria. 'The expression of the genes worked well, which is a real breakthrough, as it is difficult to express a whole antimicrobial gene cluster from a gram-positive bacterial strain directly in a gram-negative bacterium and to get the product secreted.'

Biofuel

After isolating pallidocin, the scientists were able to confirm that it is highly thermostable and exhibits extremely strong activity against specific thermophilic bacteria. Furthermore, by using the sequence of pallidocin biosynthesis genes in BAGEL4, two similar peptides were discovered in two different strains of Bacillus bacteria. These peptides, named Hyp1 and Hyp2, were also successfully expressed in the E. coli strain. 'This shows that the expression system works well for various glycocins; it is able to produce them in vivo', says Kuipers.

Pallidocin might be useful in high-temperature fermentations, which are used to produce biofuels or chemical building blocks. The higher temperature makes it easier to recover volatile products such as ethanol but also reduces the risk of contamination with common bacteria. However, contamination with thermophilic bacteria is possible. 'Both pallidocin and Hyp1 appear to be active against thermophilic bacteria and some Bacillus species,' says Kuipers. And there could be more applications: 'Contamination by thermophiles is also a problem in the food industry.'
-end-
Reference: Arnoldas Kaunietis, Andrius Buivydas, Donaldas J. ?itavičius & Oscar P. Kuipers: Heterologous biosynthesis and characterization of a glycocin from a thermophilic bacterium. Nature Communications 7 March 2019

University of Groningen

Related Bacteria Articles:

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.
Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.
Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.
Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.
Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.
How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.
The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?
Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.
Bacteria uses viral weapon against other bacteria
Bacterial cells use both a virus -- traditionally thought to be an enemy -- and a prehistoric viral protein to kill other bacteria that competes with it for food according to an international team of researchers who believe this has potential implications for future infectious disease treatment.
Drug diversity in bacteria
Bacteria produce a cocktail of various bioactive natural products in order to survive in hostile environments with competing (micro)organisms.
More Bacteria News and Bacteria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.