UGA scientists find missing links in biology of cloud formation over oceans
Scientists have known for two decades that sulfur compounds that are produced by bacterioplankton as they consume decaying algae in the ocean cycle through two paths. In one, a sulfur compound dimethylsulfide, or DMS, goes into the atmosphere, where it leads to water droplet formation – the basis of clouds that cool the Earth. In the other, a sulfur compound goes into the ocean’s food web, where it is eaten and returned to seawater.
What they haven’t known is how sulfur is routed one way or the other or why.
They also have wondered what if – in a time of growing concern about global warming – it was possible to divert the sulfur compound that goes into the oceans into the atmosphere, helping to mitigate global warming?
A study by researchers at the University of Georgia just published in Nature brings the possibility of using the sulfur cycle to mitigate global warming closer with the identification of the steps in the biochemical pathway that controls how bacteria release the sulfur compound methanethiol, or MeSH, into the microbial food web in the oceans and the genes responsible for that process.
“With our increased understanding of the sulfur cycle in the ocean,” said study co-author William (Barny) Whitman, “we are now better able to evaluate the impacts of climate change on the process and the potential for its manipulation, which has been proposed as a way to mitigate global warming.
“It’s wonderful to have this much understanding of a major biogeochemical process,” noted Whitman, distinguished research professor and head of the department of microbiology in the Franklin College of Arts and Sciences.
In addition to elucidating the steps in the pathway and identifying the responsible genes, the team of UGA microbiologists, marine scientists and chemists discovered that the pathway is found widely, not only among bacterioplankton in the ocean but also in non-marine environments.
“The big mystery about bacteria is what they are doing in nature,” Whitman said. “The organisms metabolize compounds for their own needs. We need to understand what they are getting out of it to understand what it means for the ocean, and now it will be possible to look at the environmental importance of this process and how it’s regulated.” That will help to answer the “why” of the two sulfur fates.
Co-authors of the Nature paper were UGA graduate students Chris Reisch and Vanessa Varaljay, department of microbiology; graduate student Melissa Stoudemayer and Jon Amster, professor and head, department of chemistry; and distinguished research professor Mary Ann Moran, department of marine sciences—all in the Franklin College of Arts and Sciences.
The collaborators in this study built on a line of research begun at UGA over a decade ago. Moran’s early research showed that an abundant group of bacteria known as marine roseobacters play a role in moving dimethylsulfonioproprionate (DMSP), the chemical made by marine algae and released into the water upon their death, into the atmosphere as the compound dimethylsulfide (DMS).
In 2006, Moran’s research group discovered in marine bacteria the first step in the process of turning DMSP into MeSH, instead of sending sulfur into the atmosphere. And in 2008, Moran’s doctoral student Erinn Howard, in collaboration with Whitman’s lab, discovered the gene that allows marine roseobacters to keep sulfur in the ocean.
With funding from the National Science Foundation and the Gordon and Betty Moore Foundation, the UGA researchers have now identified the rest of the pathway, including identifying two previously unknown but related chemical compounds that serve as intermediates between MMPA, the first product of degraded DMSP, and MeSH, the final product.
The collaboration with UGA chemists using high-resolution mass spectrometry made it possible for the researchers to identify the compounds. A major surprise was the presence of Coenzyme A (CoA), a large molecule important in metabolism, in the intermediate compounds.
“We weren’t really expecting CoA to be involved,” said Reisch, who was part of the UGA group that five years ago identified the first step in the pathway that produces MeSH. “We thought they would be smaller fatty acids.”
Wait a minute – clouds cool the earth? I thought it had been decided
by consensus that clouds cause warming.
One is confused.
Oh pu-leeease! No matter how far our understanding of various contributors to climate change may be, I cannot see any credibility in any suggestion that this understanding will give us – mere humans – the knowledge to actually halt or slow, or “mitigate” climate change. The oceans are VAST. The number of processes and influences and forcings and feedbacks are VAST, and infinitely complex. There is nothing anyone can do to change the climate in any pre-calculated way. Nature is bigger than Man, and any suggestion to the contrary is pure God-complex arrogance. Still, that sums up the whole CAGW movement.
The formation of MeSH from DMSP has been known since the early 1990’s.
Ronald Kiene has studied this reaction in ocean waters in detail.
Is it possible that our Ultra Low Sulfur diesel is inadvertently leading to less cloud formation, less rainfall and increasing global surface temps?
Maybe we need to rethink ULS diesel. Additionally, we now inject urea into our diesel exhaust systems to decrease particulates even further. However; the process increases CO2 concentration above the normal diesel exhaust levels. Not sure what other effects there might be, but putting Urea into the exhaust stream to reduce pollution has always seemed like a bit of a boondoggle to me. It costs about $5000 per truck to do.
Seems like every time we try to accomplish some ephemeral ‘save the planet’ type goal, we end up going backwards or creating problems we hadn’t thought of.
Sisyphus lives!
Is this the same UofGa marine lab that discovered a new coral disease….
…only for us to tell them that fire worms eat the tips off of acropora every fall
or the same UofGa marine lab that was caught illegally harvesting corals and lost their permits to collect
nahhhhh, can’t be
The British chemist Lovelock was the first to discover DMSO in the open oceans in the early 1970s and suggested a connection to algae.
DMSO is how the open ocean birds know it’s time for breakfast. During the day, it interacts with water and sunlight to become sulfuric acid.
In addition , you can’t ignore the salt. Between sulfuric acid and salt, the oceans are one huge continuous erupting water volcano.
Essentially this is the basis of work by Svensmark and Calder – the interactions of medium energy muons with sulfuric acid to produce low level clouds over the open oceans.
Incidentally, how did the seeding of plankton with iron work out?
What irritates/scares me is that they identify a natural system that automatically, without human interaction or taxpayer cost provides a natural negative feedback to increased temperatures and the first thing they want to do is to FIDDLE with it. D**n it all, the natural systems work — leave them alone!
Agile Aspect says:
May 12, 2011 at 10:08 am
“The British chemist Lovelock was the first to discover DMSO in the open oceans in the early 1970s and suggested a connection to algae. ”
It’s a pity that he’s crazy.
Opps – I meant DMS – not DMSO.
DirkH says:
May 12, 2011 at 12:30 pm
“They also should have wondered what if – in a time of
growingfalling concern about global warming – it was possible to divert the sulfur compound that goes into the oceans into the atmosphere, helping tomitigateexacerbate globalwarmingcooling.”Thar, aallll figsd.
DirkH says:
May 12, 2011 at 12:30
It’s a pity that he’s crazy.
;————————————
Yes it is. But he did make an important discovery by thinking outside the box.
F. Ross says:
May 12, 2011 at 9:45 am
Wait a minute – clouds cool the earth? I thought it had been decided
by consensus that clouds cause warming.
;————————————————-
I thought it was warming causes clouds.
I’m really pleased I’m a farmer not a scientist. I just think nature is marvellous and it works fine. Sometimes in my favour sometimes not and I really can’t do anything either way except work with it. I only have to know that some things work not how they work. The best thing that has come out of the AGW scam is that far from being settled the science is showing just how little we know and knowing so little how foolish we would be to make great decisions based on partial knowledge.