Featured Research

from universities, journals, and other organizations

Life In Deadly Conditions: Researchers Sequence The Genome Of A Microbiological Master Of Adaptation

October 19, 2005
Max Planck Society
The genome of another micro-organism which lives under extreme conditions has been sequenced. Scientists at the Department of Membrane Biochemistry at the Max Planck Institute of Biochemistry have analysed the genome of Natronomonas pharaonis and uncovered the survival strategies with which the archaeon can best thrive in deadly environmental conditions. In the latest edition of the international journal Genome Research, Professor Dieter Oesterhelt and his colleagues present their research.

Left, electron-microscopic images of the single-cell Natronomona pharaonis, which prospers in hostile salt-saturated lakes. Right, Lake Zuf in Wadi Natrun, Egypt, where the organism was found. With the sequencing of the genome, the micro-organism’s survival strategies can now be clarified. Image: Max Planck Institute for Biochemistry (left); A.J. Scortland, Antiquity 77, No 296, June 2003 (right)

Related Articles

Archaea,small single-celled organisms, are particularly interesting forscientists because they are able to live under extreme environmentalconditions, for instance under high salt concentrations, highpH-values, or high temperatures. Nature’s masters of adaptation, theyare model organisms from which researchers can draw conclusions aboutthe first organisms on earth. The scientists studied mechanisms thatmake survival possible for the single-celled organisms, which arerod-shaped and are only five hundredths of a millimetre in size. At theDepartment of Membrane Biochemistry, led by Professor DieterOesterhelt, Max Planck researchers have shown, using genomic andproteomic methods combined with physiological experiments, how toexplain the amazing abilities of these extreme organisms.

FriedhelmPfeiffer, the research group’s bioinformatics expert, created adatabase for halophile (Greek "salt-lovers") archaea, called HaloLex(see link below). Using the database, genetic and protein data aboutthe organisms is tied to information about their structure andfunction. The newest genome on HaloLex is now that of Natronomonaspharaonis, whose genetic information was made available by MichaelaFalb, Friedhelm Pfeiffer, Peter Palm, Karin Rodewald, Volker Hickmann,Jörg Tittor and Dieter Oesterhelt. This information is made of some 2.6million base pairs (about one thousandth of the human genome), andencodes the synthesis of 2,843 proteins.

Natronomonas pharaonishas to deal with two different kinds of life-threatening conditions. Itwas found in pools which are strongly alkaline (pH-value of about 11)with an extremely high salt concentration (over 300 grams of salt perlitre of water). The high pH-values are about the same as lye soap andthe salt content that of the Dead Sea. As far as the salt content isconcerned, Natronomonas pharaonis behaves like closely relatedorganisms - for example, Halobacterium salinarum, the "house pet" ofDieter Oesterhelt’s department. In contrast to other salt-tolerantorganisms, halophile archaea have an extremely high salt concentrationinside of their cells. These levels of salt concentration cannotusually support proteins, the critical functional components of livingcells. But the greater portion of amino-acid building blocks in theproteomes of halophile archaea make it possible for the proteins toremain stabile, even in high salt concentrations. To survive among theextremely high pH-values, Natronomonas pharaonis also has a moderatelyincreased pH-value inside its cells.

The cellular components thatare in direct contact with the brine around them need their ownadaptation strategies. These components are the cell membrane and theproteins that have to function outside the cell. Michaela Falbdiscovered, using theoretical analysis as part of her doctoral thesis,that Natronomonas pharaonis has a particularly large number of proteinsattached to lipid molecules, anchoring it to the cell membrane.

Importantfunctions of the energy metabolism - for example, the respiratory chain- are embedded in the cell membrane and have to be adapted to theadverse external conditions. Despite a detailed bioinformatic analysisof the genome, it was still unclear whether Natronomonas pharaonis hasa respiratory chain and which ions would play a role in itsfunctioning. The bioinformatics expert Michaela Falb and biochemistJörg Tittor thus designed additional experimental studies which showedthat Natronomonas pharaonis does indeed have a functioning respiratorychain, which amazingly, and in contrast to other organisms that grow inalkaline conditions, functions with a "normal" proton. The Max Planckresearchers could thus refute the paradigm, dominant until now, thatorganisms in alkaline conditions have to switch to other ions (forexample, sodium, Na+).

A higher pH-value leads to thedepletion of ammonium. Because ammonium nitrate is a key building blockof amino acids, the tiny organism should have problems synthesising it.Michaela Falb discovered in the genome a number of ways thatNatronomonas pharaonis can take optimal advantage of the low incidenceof nitrogen: through the uptake and metabolism of nitrate and urea, aswell as the efficient uptake of ammonia.

The co-operation oftheoretically and experimentally-oriented researchers shed light onother questions. The bioinformatics experts were able to predict thatNatronomonas pharaonis can by itself produce vitamins and amino acids.Thus, the growth medium for the culture of the single-celled organismcould be significantly simplified.

Dieter Oesterhelt explainsthat "the comparison with other halophile archaea we have studied showsthat these organisms have a high plasticity with which they can adaptto the varying, extreme environmental conditions. The frugality ofNatronomonas pharaonis, with the possibility of simplifying thenutrient solution, opens new possibilities for experimentallyinvestigating the metabolic network. The data we thus acquire make upan important foundation for developing and testing metabolic models inthe framework of systemic biological studies and in interdisciplinaryco-operation with mathematicians."

Story Source:

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

Cite This Page:

Max Planck Society. "Life In Deadly Conditions: Researchers Sequence The Genome Of A Microbiological Master Of Adaptation." ScienceDaily. ScienceDaily, 19 October 2005. <www.sciencedaily.com/releases/2005/10/051018224200.htm>.
Max Planck Society. (2005, October 19). Life In Deadly Conditions: Researchers Sequence The Genome Of A Microbiological Master Of Adaptation. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2005/10/051018224200.htm
Max Planck Society. "Life In Deadly Conditions: Researchers Sequence The Genome Of A Microbiological Master Of Adaptation." ScienceDaily. www.sciencedaily.com/releases/2005/10/051018224200.htm (accessed December 22, 2014).

Share This

More From ScienceDaily

More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) — Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) — A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) — Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
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.


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


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