Switching between mobile and sessile life styles is typical of many species of the bacteria of the Roseobacter group. Microbiologists at the Leibniz Institute DSMZ have now demonstrated that the genes responsible for this, usually are located outside the bacterial chromosome on a single plasmid. The study show that even characteristics as complex as the ability of biofilm formation can be passed on via horizontal gene transfer. Within the Roseobacter group, this has actually happened multiple times.
Their diverse metabolic characteristics make bacteria of the Roseobacter group some of the most abundant microorganisms in nutrient-rich coastal waters. Roseobacters together with other bacteria form highly complex biofilms that have been dubbed “cities of microbes”.
However, they can also be found swimming freely in the oceans. Switching between mobile and sessile life styles is typical of many species of these marine bacteria. This flexibility is based on their ability to actively move with the help of flagella, while they are also capable of reversibly attaching to surfaces.
Jörn Petersen, a microbiologist at the Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, in Braunschweig, Germany, and his colleagues have now demonstrated that the genes responsible for biofilm formation usually are located outside the bacterial chromosome on a single plasmid.
They reached this conclusion based on a physiological and genetic study of 33 Roseobacter strains. First, Petersen and colleagues showed that all bacteria that are efficient biofilm formers also are mobile. By removing the plasmids responsible for biofilm formation, they were able to demonstrate that the bacteria not only lost their ability of adhering to surfaces, but also their swimming capability.
“Thus, it is obvious that the responsible genes are located on these extrachromosomal elements,” said Petersen. Genes that are passed on via plasmids are able to cross the species boundary relatively easily. “Our studies show that even characteristics as complex as the ability of biofilm formation can be passed on via horizontal gene transfer,” said Petersen. Within the Roseobacter group, this type of horizontal gene transfer has actually happened multiple times, reflecting the great importance of plasmids for quick adaptation to new ecological niches.
The majority of the 33 Roseobacter strains studied were type strains, i.e., reference strains representative of the world’s bacterial diversity, which are archived in the DSMZ collection. Unlike previous studies, the DSMZ researchers genetically analyzed the group across its full evolutionary range. “Our present studies by far exceed anecdotal findings previously reported for individual model organisms. Moreover, they demonstrate the close link between basic research and collection activities here at DSMZ. As such, they also reflect DSMZ’s importance as one of the world’s leading resource centers for biological materials,” said Petersen.
The studies were supported by the Deutsche Forschungsgemeinschaft (DFG) and are part of the DFG Collaborative Research Center TRR51, “Roseobacter.” Results were recently published in Nature Publishing Group’s distinguished ISME Journal.
Michael V, Frank O, Bartling P, Scheuner C, Göker M, Brinkmann H, Petersen J. (2016). Biofilm plasmids with a rhamnose operon are widely distributed determinants of the ʻswim-or-stickʼ lifestyle in roseobacers. ISME J [Epub ahead of print]. http://doi.org/10.1038/ismej.2016.30
Petersen J, Frank O, Göker M, Pradella S. (2013). Extrachromosomal, extraordinary and essential - the plasmids of the Roseobacter clade. Applied Microbiology and Biotechnology 97: 2805-2815.
Frank O, Michael V, Päuker O, Boedeker C, Jogler C, Rohde M, Petersen J. (2015). Plasmid curing and the loss of grip--the 65-kb replicon of Phaeobacter inhibens DSM 17395 is required for biofilm formation, motility and the colonization of marine algae. Systematic and Applied Microbiology 38:120-127.
PD Dr. Jörn Petersen
Department Protists and Cyanobacteria (PuC)
Head of Projekt A5 „Plasmide“ Transregio Sonderforschungsbreich (TRR51)
Phone.: 0531 2616-209
About Leibniz Institute DSMZ
The Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures GmbH is a Leibniz Association institution. Offering comprehensive scientific services and a wide range of biological materials it has been a partner for research and industry organizations worldwide for decades. DSMZ is one of the largest biological resource centers of its kind to be compliant with the internationally recognized quality norm ISO 9001:2008. As a patent depository, DSMZ currently offers the only option in Germany of accepting biological materials according to the requirements of the Budapest Treaty. The second major function of DSMZ, in addition to its scientific services, is its collection-related research. The Brunswick (Braunschweig), Germany, based collection has existed for 42 years and holds more than 52,000 cultures and biomaterials. DSMZ is the most diverse collection worldwide: In addition to fungi, yeasts, bacteria, and archea, it is home to human and animal cell cultures, plant viruses, and plan cell cultures that are archived and studied there. http://www.dsmz.de
Christian Engel | idw - Informationsdienst Wissenschaft
Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg
Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
19.10.2017 | Materials Sciences
19.10.2017 | Materials Sciences
19.10.2017 | Physics and Astronomy