Featured Research

from universities, journals, and other organizations

Potential Sources Of 'Rain-Making' Bacteria In The Atmosphere Identified

Date:
November 20, 2008
Source:
Louisiana State University
Summary:
Scientists recently found evidence that bacteria and biological cells are the most efficient ice-forming catalysts in precipitation from locations around the globe. The formation of ice in clouds is important in the processes that lead to snow and rain. Ice-nucleating bacteria -- which have been referred to as "rain-making bacteria" -- may be significant triggers of freezing in clouds and influence the water cycle.

Cells of ice-nucleating bacteria (dots) entrapped in ice crystals.
Credit: Image courtesy of Louisiana State University

Brent Christner, assistant professor of biological sciences at LSU, recently found evidence that bacteria and biological cells are the most efficient ice-forming catalysts in precipitation from locations around the globe. The formation of ice in clouds is important in the processes that lead to snow and rain. Ice-nucleating bacteria – which have been referred to as “rain-making bacteria” – may be significant triggers of freezing in clouds and influence the water cycle.

These findings, which take a big step toward filling the gaps in scientific understanding of ice nuclei in the atmosphere, will be published in the Proceedings of the National Academy of Sciences during the week of Nov. 17.

Christner’s team, which includes Kevin McCarter and Rongman Cai of LSU’s Department of Experimental Statistics, and collaborators at INRA in France and Montana State University, had previously demonstrated the presence of ice nucleating bacteria in precipitation. However, the source remained elusive.

“To address this, we examined the correlations between the presence of biological ice nuclei in precipitation and the composition of aerosols co-deposited in the precipitation,” said Christner. The chemical composition of the aerosols revealed information on their source and the potential environments from which the biological ice nuclei could have originated.

“Our models can accurately predict the concentrations of cells and biological ice nucleators in precipitation using a relatively small number of variables,” he said. “The data provides a first glimpse of the conditions that appear to favor the distribution of biological ice nuclei in the atmosphere and will be useful for predicting their abundance in other contexts.”

The study concludes that vegetation and soils are an important source of biological ice nuclei to the atmosphere at some geographical locations. Though they were detected in snow from places as remote as Antarctica, ice nucleating bacteria may also exist in the ocean, or alternatively, are able to travel large distances in the atmosphere. “The atmosphere provides an efficient conduit for microbial dispersal on a global scale,” said Christner.

Most known ice-nucleating bacteria are plant pathogens, which are basically germs that can cause disease and freezing injury in plants. According to Christner, agricultural losses from ice nucleating bacteria, such as Pseudomonas syringae, often exceed $1 billion dollars per year in the United States, so understanding their mode of dispersal is essential for mitigating their impact on crops. It is possible that dissemination through precipitation is a crucial facet of the life cycle for some plant bacteria, allowing them to colonize new hosts.

The new results provide much territory for further study. For example, many of the variables important for predicting the cell and biological ice nuclei concentration in precipitation are nutrients vital for growth and production of these ice nucleators.

“Previous work has shown that microbes can metabolize and grow in clouds, meaning that the atmosphere may represent an environment for life,” said Christner. “It is possible that cloud-borne microbes could ‘turn on’ their ice nuclear in the atmosphere and subsequently be returned to the ground in snow or rain. This is a very exciting possibility that further research could unearth.”


Story Source:

The above story is based on materials provided by Louisiana State University. Note: Materials may be edited for content and length.


Cite This Page:

Louisiana State University. "Potential Sources Of 'Rain-Making' Bacteria In The Atmosphere Identified." ScienceDaily. ScienceDaily, 20 November 2008. <www.sciencedaily.com/releases/2008/11/081119171523.htm>.
Louisiana State University. (2008, November 20). Potential Sources Of 'Rain-Making' Bacteria In The Atmosphere Identified. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2008/11/081119171523.htm
Louisiana State University. "Potential Sources Of 'Rain-Making' Bacteria In The Atmosphere Identified." ScienceDaily. www.sciencedaily.com/releases/2008/11/081119171523.htm (accessed September 16, 2014).

Share This



More Earth & Climate News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Pakistan's 'killer Mountain' Fails to Draw Tourists After Attack

Pakistan's 'killer Mountain' Fails to Draw Tourists After Attack

AFP (Sep. 12, 2014) In June 2013, 10 foreign mountaineers and their guide were murdered on Nanga Parbat, an iconic peak that stands at 8,126m tall in northern Pakisan. Duration: 02:34 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