Featured Research

from universities, journals, and other organizations

Division of labor in the test tube

Date:
December 2, 2013
Source:
Max Planck Institute for Chemical Ecology
Summary:
The division of labor is more efficient than a struggle through life without help from others -- this also applies to microorganisms. Researchers came to this conclusion when they performed experiments with bacteria that were deficient in the production of certain amino acids and depended on a partner to provide the missing nutrient. Bacterial strains that complemented each other's need showed a fitness increase of 20 percent relative to a non-deficient strain without partner.

Bacteria that divide their metabolic labor (left colony) grow faster than bacterial cells that produce all amino acids on their own (right colony).
Credit: Samay Pande, Max Planck Institute for Chemical Ecology

The division of labor is more efficient than a struggle through life without help from others -- this is also true for microorganisms. 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.

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!

Microbial communities

"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.


Story Source:

The above story is based on materials provided by Max Planck Institute for Chemical Ecology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Samay Pande, Holger Merker, Katrin Bohl, Michael Reichelt, Stefan Schuster, Luís F de Figueiredo, Christoph Kaleta, Christian Kost. Fitness and stability of obligate cross-feeding interactions that emerge upon gene loss in bacteria. The ISME Journal, 2013; DOI: 10.1038/ismej.2013.211

Cite This Page:

Max Planck Institute for Chemical Ecology. "Division of labor in the test tube." ScienceDaily. ScienceDaily, 2 December 2013. <www.sciencedaily.com/releases/2013/12/131202134624.htm>.
Max Planck Institute for Chemical Ecology. (2013, December 2). Division of labor in the test tube. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2013/12/131202134624.htm
Max Planck Institute for Chemical Ecology. "Division of labor in the test tube." ScienceDaily. www.sciencedaily.com/releases/2013/12/131202134624.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) — Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) — An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Adorable Video of Baby Rhino and Lamb Friend Playing

Adorable Video of Baby Rhino and Lamb Friend Playing

Buzz60 (Oct. 20, 2014) — Gertjie the Rhino and Lammie the Lamb are teaching the world about animal conservation and friendship. TC Newman (@PurpleTCNewman) has the adorable video! Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins