The division of labor is more efficient than a struggle through life without help from others – this is also true for microorganisms.
Bacteria that divide their metabolic labor (left colony) grow faster than bacterial cells that produce all amino acids on their own (right colony).
S. Pande / MPI for Chemical Ecology
Researchers from Research Group Experimental Ecology and Evolution at the Max Planck Institute for Chemical Ecology and their colleagues at the Friedrich Schiller University in Jena, Germany came to this conclusion when they performed experiments with microbes.
The scientists worked with bacteria that were deficient in the production of a certain amino acid and therefore depended on a partner to provide the missing nutrient. Bacterial strains that complemented each other’s need by providing the required amino acid showed a fitness increase of about 20% relative to a non-deficient strain without partner.
This result helps to explain why cooperation is such a widespread model of success in nature. (The ISME Journal, 28 November 2013, DOI: 10.1038/ismej.2013.211)
Ecology and evolution: close relatives
Each life form on our planet has to adapt to its environment as good as it can. Apart from getting used to climate conditions and food supply, each species must get along with other organisms in the habitat. In the course of evolution species adapt continuously to each other and to the environment by changing their genetic features. This is why cold resistant species live at the poles and heat resistant species in the deserts. Also nutritional needs and metabolic regulation underlie the principle of evolution. So let’s take a look at the world of microbes in this context!
“No matter where you look: Microbial communities can be found in almost every habitat you can think of,” says Christian Kost, leader of the research group “Experimental Ecology and Evolution” at the Max Planck Institute for Chemical Ecology in Jena, Germany. Microbes often live in symbiosis with higher organisms, but they also cooperate with each other in order to optimally utilize the resources that are available to them. Interestingly, a look at the genome of cooperating bacterial strains shows that some of them are unable to perform all vital metabolic functions on their own. Instead, they rely on their cooperative partner. Their environment, that is to say other organisms, provides the nutrients they cannot produce themselves anymore. However, the result of the cooperation is a risky dependency: If one partner is lost, the other dies as well. Can such a dependency in fact be a trait that is selected for and which is maintained for a longer period in a bacterial population? Is this assumption compatible with Darwin’s theory of the “survival of the fittest”? If so, cooperating partners should perform as good or even better than microbes without partner in terms of fitness.
Synthetic Ecology: simulating ecological parameters in a test tube
To bring a naturally evolved symbiotic community from the real world into the lab to study such cooperation, is often very difficult. Therefore, scientists used a synthetic model: Escherichia coli bacteria were genetically modified in such a way that one bacterial strain was unable to produce a certain amino acid anymore, such as tryptophan, but produced all other amino acids in high concentrations. If this strain grows in a culture with another strain unable to produce arginine, another amino acid, both strains are able to feed each other. Amazingly, such co-culture experiments showed that the growth of these bacterial cells was increased by 20% in comparison to the unmodified wild-type strain that was able to produce all essential amino acid by itself. The inability of the deficient strain to produce an essential amino acid had a positive effect on its growth when a partner was present that compensated this loss. This can be explained by the considerably reduced energy costs both strains had to invest for producing the exchanged amino acids. Specializing on the production of certain, but not all necessary amino acids made the bacterial cells more efficient and thus resulted in faster growth. Interestingly, the two cooperating, amino acid exchanging strains even outcompeted a self-sustaining wild-type strain.
The research results from Christian Kost’s lab illustrate why symbiotic relationships with bacteria are so prevalent. In the course of evolution, an association may get so close that the mutualistic partners merge into a new, multicellular organism.
The research project was funded by the Volkswagen Foundation, the Jena School for Microbial Communication, the Fundação Calouste Gulbenkian and the Fundação para a Ciência e a Tecnologia as well as Siemens SA Portugal. [JWK/AO]Original Publication:
Download of high resolution pictures on http://www.ice.mpg.de/ext/735.html
Angela Overmeyer | Max-Planck-Institut
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences