Featured Research

from universities, journals, and other organizations

Uncovering the tricks of nature's ice-seeding bacteria

Date:
October 23, 2013
Source:
American Institute of Physics
Summary:
New discoveries could impact applications ranging from artificial snowmaking to global climate models.

Like the Marvel Comics superhero Iceman, some bacteria have harnessed frozen water as a weapon. Species such as Pseudomonas syringae have special proteins embedded in their outer membranes that help ice crystals form, and they use them to trigger frost formation at warmer than normal temperatures on plants, later invading through the damaged tissue. When the bacteria die, many of the proteins are wafted up into the atmosphere, where they can alter the weather by seeding clouds and precipitation.

Now scientists from Germany have observed for the first time the step-by-step, microscopic-level action of P. syringae's ice-nucleating proteins locking water molecules in place to form ice. The team will present their findings at the AVS 60th International Symposium and Exhibition, held Oct. 27 -- Nov. 1 in Long Beach, Calif.

"Ice nucleating proteins are the most effective ice nucleators known," said Tobias Weidner, leader of the surface protein group at the Max Planck Institute for Polymer Research. The proteins jump-start the process of ice crystal formation so well that dried ice-nucleating bacteria are often used as additives in snowmakers.

Although scientists discovered ice-nucleating proteins decades ago, little is known about how they actually work. Weidner and his team tackled the mystery with a powerful tool called spectroscopy that can decipher patterns in the interaction between light and matter to visualize the freezing process in layers of materials only a few molecules thick.

The researchers prepared a sample of fragments of P. syringae bacteria that they spread over water to form a surface film. As the temperature was lowered from room temperature to near freezing levels the scientists probed the interface between the bacterial proteins and the water with two laser beams. The beams combined within the sample and a single beam was emitted back, carrying with it information about how the protein and water molecules move and interact.

By analyzing the returning light beam's frequency components, Weidner and his colleagues found a surprisingly dramatic result: as the temperature approached zero degrees Celcius the water molecules at the ice-nucleating protein surface suddenly became more ordered and the molecular motions become sluggish. They also found that thermal energy was very efficiently removed from the surrounding water. The results indicate that ice nucleating proteins might have a specific mechanism for heat removal and ordering water that is activated at low temperatures, Weidner said.

"We were very surprised by these results," Weidner added. "When we first saw the dramatic increase of water order with lower temperatures we believed it was an artifact." The movements of the water molecules near the ice-nucleating protein was very different than the way water had interacted with the many other proteins, lipids, carbohydrates, and other biomolecules the team had studied.

Recent studies have shown that large numbers of bacterial ice-nucleating proteins become airborne over areas like the Amazon rainforest and can spread around the globe. The proteins are among the most effective promoters of ice particle formation in the atmosphere, and have the potential to significantly influence weather patterns. Learning how P. syringae triggers frost could help teach researchers how ice particle formation occurs in the upper atmosphere.

"Understanding at the microscopic level -- down to the interaction of specific protein sites with water molecules -- the mechanism of protein-induced atmospheric ice formation will help us understand biogenic impacts on atmospheric processes and the climate," Weidner said. For a more detailed picture of protein-water interactions it will also be important to combine their spectroscopic results with computer models, he said.


Story Source:

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


Cite This Page:

American Institute of Physics. "Uncovering the tricks of nature's ice-seeding bacteria." ScienceDaily. ScienceDaily, 23 October 2013. <www.sciencedaily.com/releases/2013/10/131023141119.htm>.
American Institute of Physics. (2013, October 23). Uncovering the tricks of nature's ice-seeding bacteria. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2013/10/131023141119.htm
American Institute of Physics. "Uncovering the tricks of nature's ice-seeding bacteria." ScienceDaily. www.sciencedaily.com/releases/2013/10/131023141119.htm (accessed October 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3D Printed Instruments Make Sweet Music in Sweden

3D Printed Instruments Make Sweet Music in Sweden

Reuters - Innovations Video Online (Oct. 23, 2014) — Students from Lund University's Malmo Academy of Music are believed to be the world's first band to all use 3D printed instruments. The guitar, bass guitar, keyboard and drums were built by Olaf Diegel, professor of product development, who says 3D printing allows musicians to design an instrument to their exact specifications. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
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

 

Space & Time

Matter & Energy

Computers & Math

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