Featured Research

from universities, journals, and other organizations

Bacteria Are Models Of Efficiency

Date:
February 6, 2009
Source:
Weizmann Institute of Science
Summary:
A mathematical model has revealed how single celled organismsregulatetheir activities for maximum efficiency.

The bacterium Escherichia coli, one of the best-studied single-celled organisms around, is a master of industrial efficiency. This bacterium can be thought of as a factory with just one product: itself. It exists to make copies of itself, and its business plan is to make them at the lowest possible cost, with the greatest possible efficiency.

Efficiency, in the case of a bacterium, can be defined by the energy and resources it uses to maintain its plant and produce new cells, versus the time it expends on the task.

Dr. Tsvi Tlusty and research student Arbel Tadmor of the Physics of Complex Systems Department developed a mathematical model for evaluating the efficiency of these microscopic production plants. Their model, which recently appeared in the online journal PLoS Computational Biology, uses only five remarkably simple equations to check the efficiency of these complex factory systems.

The equations look at two components of the protein production process: ribosomes – the machinery in which proteins are produced – and RNA polymerase – an enzyme that copies the genetic code for protein production onto strands of messenger RNA for further translation into proteins. RNA polymerase is thus a sort of work ‘supervisor’ that keeps protein production running smoothly, checks the specs and sets the pace.

The first equation assesses the production rate of the ribosomes themselves; the second the protein output of the ribosomes; the third the production of RNA polymerase. The last two equations deal with how the cell assigns the available ribosomes and polymerases to the various tasks of creating other proteins, more ribosomes or more polymerases.

The theoretical model was tested in real bacteria. Do bacteria ‘weigh’ the costs of constructing and maintaining their protein production machinery against the gains to be had from being able to produce more proteins in less time? What happens when a critical piece of equipment is in short supply, say a main ribosome protein? Tlusty and Tadmor found that their model was able to accurately predict how an E. coli would change its production strategy to maximize efficiency following disruptions in the work flow caused by experimental changes to genes with important cellular functions.

What’s the optimum? The model predicts that a bacterium, for instance, should have seven genes for ribosome production. It turns out that that’s exactly the number an average E. coli cell has. Bacteria having five or nine get a much lower efficiency rating. Evolution, in other words, is a master efficiency expert for living factories, meeting any challenges that arise as production conditions change.

Dr. Tsvi Tlusty’s research is supported by the Clore Center for Biological Physics.


Story Source:

The above story is based on materials provided by Weizmann Institute of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tadmor et al. A Coarse-Grained Biophysical Model of E. coli and Its Application to Perturbation of the rRNA Operon Copy Number. PLoS Computational Biology, 2008; 4 (5): e1000038 DOI: 10.1371/journal.pcbi.1000038

Cite This Page:

Weizmann Institute of Science. "Bacteria Are Models Of Efficiency." ScienceDaily. ScienceDaily, 6 February 2009. <www.sciencedaily.com/releases/2009/02/090204101254.htm>.
Weizmann Institute of Science. (2009, February 6). Bacteria Are Models Of Efficiency. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2009/02/090204101254.htm
Weizmann Institute of Science. "Bacteria Are Models Of Efficiency." ScienceDaily. www.sciencedaily.com/releases/2009/02/090204101254.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Newsy (July 30, 2014) The Peace Corps is one of several U.S.-based organizations to pull workers out of West Africa because of the Ebola outbreak. Video provided by Newsy
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
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:
from the past week

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