Date: August 23, 2017
Source: University of Alberta
Summary: Microbiologists have now provided unparalleled insight into the Earth's nitrogen cycle, identifying and characterizing the ammonia-oxidizing microbe, Nitrospira inopinata.
New research from University of Alberta and University of Vienna microbiologists provides unparalleled insight into the Earth's nitrogen cycle, identifying and characterizing the ammonia-oxidizing microbe, Nitrospira inopinata. The findings, explained Lisa Stein, co-author and professor of biology, have significant implications for climate change research.
"I consider nitrogen the camouflaged beast in our midst," said Stein.
"Humans are now responsible for adding more fixed nitrogen, in the form of ammonium, to the environment than all natural sources combined. Because of that, the nitrogen cycle has been identified as the most unbalanced biogeochemical cycle on the planet."
The Camouflaged Beast
Earth's nitrogen cycle has been thrown significantly off balance by the process we use to make fertilizer, known as the Haber-Bosch process, which adds massive quantities of fixed nitrogen, or ammonium, to the environment. Downstream effects of excess ammonium has huge environmental implications, from dead zones in our oceans to a greenhouse gas effect 300 times that of carbon dioxide on a molecule to molecule basis.
Isolation and characterization of the Nitrospira inopinata microbe, Stein said, could hold the answers for Earth's nitrogen problem.
Practical Applications
"The Nitrospira inopinata microbe is an ammonium sponge, outcompeting nearly all other bacteria and archaea in its oxidation of ammonium in the environment," explained Stein. "Now that we know how efficient this microbe is, we can explore many practical applications to reduce the amount of ammonium that contributes to environmental problems in our atmosphere, water, and soil."
The applications range from wastewater treatment, with the development of more efficient biofilms, to drinking water and soil purification to climate change research.
"An efficient complete ammonia oxidizer, such as Nitrospira inopinata, may produce less nitrous oxide," explained Kits. "By encouraging our microbe to outgrow other, incomplete oxidizers, we may, in turn, reduce their contribution to the greenhouse gas effect. Further investigation is required."
Story Source:
University of Alberta. "New microbe has potential to help rebalance Earth's nitrogen cycle." ScienceDaily. ScienceDaily, 23 August 2017. www.sciencedaily.com/releases/2017/08/170823142427.htm
Showing posts with label Nitrogen. Show all posts
Showing posts with label Nitrogen. Show all posts
Friday, August 25, 2017
Friday, January 27, 2017
Researchers Discover Greenhouse Bypass for Nitrogen
Finding May Offer Farmers a Way to Reduce Harmful Emissions from Fertilized Soil
Date: January 18, 2017
Source: Virginia Institute of Marine Science
Summary: Production of a potent greenhouse gas can be bypassed as soil nitrogen breaks down into unreactive atmospheric N2, an international team of researchers has discovered.
Associate professor BK Song of the Virginia Institute of Marine Science collects water samples for analysis of nitrogen and microbes.
Credit: © D. Malmquist/VIMS.
Those concerned with water quality are familiar with nitrogen as a major pollutant whose excess runoff into coastal waters can lead to algal blooms and low-oxygen dead zones. Perhaps less familiar is the significant role that a form of nitrogen gas plays in greenhouse warming and the destruction of Earth's ozone layer.
Now, an international group of scientists including Dr. B.K. Song of William & Mary's Virginia Institute of Marine Science have discovered that production of this potent greenhouse gas -- known as N2O or nitrous oxide -- can be bypassed as complex nitrogen compounds in soil, water, and fertilizers break down into the unreactive nitrogen gas (N2) that makes up most of our atmosphere.
Their discovery, published in a recent edition of Scientific Reports, reveals an entirely new pathway in the global nitrogen cycle and could lead to new ways for farmers and others to reduce their emissions of harmful gases. The study's lead author is Rebecca Phillips of New Zealand's Landcare Research Institute, along with Landcare colleagues Andrew McMillan, Gwen Grelet, Bevan Weir, and Palmada Thilak; as well as Craig Tobias of the University of Connecticut.
Agriculture contributes more nitrous oxide to the atmosphere than any other human activity -- primarily through nitrogen fertilization. This greenhouse gas is 300 times more effective at trapping heat than carbon dioxide and 10 times more effective than methane. Nitrous oxide also moves into the stratosphere and destroys ozone.
Current wisdom holds that nitrous oxide is inevitably produced when soil nitrogen -- including fertilizer components such as ammonia, ammonium, and urea -- breaks down. It's also thought this breakdown process requires the action of microbes, and can only occur in the absence of oxygen.
The current research contradicts each of these long-held ideas.
"Our findings question the assumption that nitrous oxide is an intermediate required for formation of nitrogen gas [N2]," says Phillips. "They also throw doubt on whether microbial production of nitrous oxide must take place in the absence of oxygen."
"We now have a pathway that doesn't require microbes," adds Song. "The process of denitrification can happen abiotically, without the need for bacteria or fungi."
The team's discovery could lead to practical applications for decreasing the impacts of excess nitrogen in the environment, a topic they focused on while presenting their findings during a recent meeting in Washington D.C. sponsored by the U.S. Department of Agriculture and the National Integrated Water Quality Program.
"It might give us a way to engineer the system to reduce levels of fixed nitrogen," says Song. "By changing the types and ratios of nitrogen compounds in fertilizer, you might have a better way to reduce excess nitrogen, and to mitigate eutrophication or nutrient enrichment in nearby waters."
Phillips adds, "Further research could inform farmers of how to cultivate soil organic matter useful for nitrogen management. Organic forms of soil nitrogen, such as waste products from plants and fungi, could help convert excess inorganic nitrogen -- which would otherwise be leached into water or emitted as nitrous oxide -- into a form that isn't harmful to the environment."
However, the scientists say more research is needed to test exactly which forms of organic nitrogen are most effective. The team is now developing proposals for further funding that will allow them to investigate on-farm applications for transforming excess nitrogen from soil and water into unreactive atmospheric N2 gas without producing N2O. This may allow scientists to develop options to manage the fate of agricultural nitrogen while avoiding greenhouse-gas emissions.
Story Source:
Virginia Institute of Marine Science. "Researchers discover greenhouse bypass for nitrogen: Finding may offer farmers a way to reduce harmful emissions from fertilized soil." ScienceDaily. ScienceDaily, 18 January 2017. www.sciencedaily.com/releases/2017/01/170118163725.htm
Materials provided by Virginia Institute of Marine Science. Original written by David Malmquist.
Date: January 18, 2017
Source: Virginia Institute of Marine Science
Summary: Production of a potent greenhouse gas can be bypassed as soil nitrogen breaks down into unreactive atmospheric N2, an international team of researchers has discovered.
Associate professor BK Song of the Virginia Institute of Marine Science collects water samples for analysis of nitrogen and microbes.
Credit: © D. Malmquist/VIMS.
Those concerned with water quality are familiar with nitrogen as a major pollutant whose excess runoff into coastal waters can lead to algal blooms and low-oxygen dead zones. Perhaps less familiar is the significant role that a form of nitrogen gas plays in greenhouse warming and the destruction of Earth's ozone layer.
Now, an international group of scientists including Dr. B.K. Song of William & Mary's Virginia Institute of Marine Science have discovered that production of this potent greenhouse gas -- known as N2O or nitrous oxide -- can be bypassed as complex nitrogen compounds in soil, water, and fertilizers break down into the unreactive nitrogen gas (N2) that makes up most of our atmosphere.
Their discovery, published in a recent edition of Scientific Reports, reveals an entirely new pathway in the global nitrogen cycle and could lead to new ways for farmers and others to reduce their emissions of harmful gases. The study's lead author is Rebecca Phillips of New Zealand's Landcare Research Institute, along with Landcare colleagues Andrew McMillan, Gwen Grelet, Bevan Weir, and Palmada Thilak; as well as Craig Tobias of the University of Connecticut.
Agriculture contributes more nitrous oxide to the atmosphere than any other human activity -- primarily through nitrogen fertilization. This greenhouse gas is 300 times more effective at trapping heat than carbon dioxide and 10 times more effective than methane. Nitrous oxide also moves into the stratosphere and destroys ozone.
Current wisdom holds that nitrous oxide is inevitably produced when soil nitrogen -- including fertilizer components such as ammonia, ammonium, and urea -- breaks down. It's also thought this breakdown process requires the action of microbes, and can only occur in the absence of oxygen.
The current research contradicts each of these long-held ideas.
"Our findings question the assumption that nitrous oxide is an intermediate required for formation of nitrogen gas [N2]," says Phillips. "They also throw doubt on whether microbial production of nitrous oxide must take place in the absence of oxygen."
"We now have a pathway that doesn't require microbes," adds Song. "The process of denitrification can happen abiotically, without the need for bacteria or fungi."
The team's discovery could lead to practical applications for decreasing the impacts of excess nitrogen in the environment, a topic they focused on while presenting their findings during a recent meeting in Washington D.C. sponsored by the U.S. Department of Agriculture and the National Integrated Water Quality Program.
"It might give us a way to engineer the system to reduce levels of fixed nitrogen," says Song. "By changing the types and ratios of nitrogen compounds in fertilizer, you might have a better way to reduce excess nitrogen, and to mitigate eutrophication or nutrient enrichment in nearby waters."
Phillips adds, "Further research could inform farmers of how to cultivate soil organic matter useful for nitrogen management. Organic forms of soil nitrogen, such as waste products from plants and fungi, could help convert excess inorganic nitrogen -- which would otherwise be leached into water or emitted as nitrous oxide -- into a form that isn't harmful to the environment."
However, the scientists say more research is needed to test exactly which forms of organic nitrogen are most effective. The team is now developing proposals for further funding that will allow them to investigate on-farm applications for transforming excess nitrogen from soil and water into unreactive atmospheric N2 gas without producing N2O. This may allow scientists to develop options to manage the fate of agricultural nitrogen while avoiding greenhouse-gas emissions.
Story Source:
Virginia Institute of Marine Science. "Researchers discover greenhouse bypass for nitrogen: Finding may offer farmers a way to reduce harmful emissions from fertilized soil." ScienceDaily. ScienceDaily, 18 January 2017. www.sciencedaily.com/releases/2017/01/170118163725.htm
Materials provided by Virginia Institute of Marine Science. Original written by David Malmquist.
Friday, December 9, 2016
Bacterial Mechanism Converts Nitrogen to Greenhouse Gas
Author: Blaine Friedlander
Source: Cornell Chronicle
Cornell researchers have discovered a biological mechanism that helps convert nitrogen-based fertilizer into nitrous oxide, an ozone-depleting greenhouse gas. The paper was published online Nov. 17 in the Proceedings of the National Academy of Sciences.
“The first key to plugging a leak is finding the leak,” said Kyle Lancaster, assistant professor of chemistry and chemical biology, and senior author on the research. “We now know the key to the leak and what’s leading to it. Nitrous oxide is becoming quite significant in the atmosphere, as there has been a 120 percent increase of nitrous oxide in our atmosphere since pre-industrial times.”
Lancaster, along with postdoctoral researcher Jonathan D. Caranto and chemistry doctoral candidate Avery C. Vilbert, showed that an enzyme made by the ammonia oxidizing bacterium Nitrosomonas europaea, cytochrome P460, produces nitrous oxide after the organism turns ammonia into an intermediate metabolite called hydroxylamine.
N. europaea and similar “ammonia-oxidizing bacteria” use hydroxylamine as their fuel source, but too much hydroxylamine can be harmful – and the resulting production of nitrous oxide is a chemical coping strategy.
Lancaster and his colleagues hypothesize that when ammonia-oxidizing bacteria are exposed to high levels of nitrogen compounds, such as in crop fields or wastewater treatment plants, then nitrous oxide production via cytochrome P460 will ramp up.
In the atmosphere, greenhouse gases are a soup of many species, and Lancaster explained that nitrous oxide has 300 times the potency of carbon dioxide. “That’s a staggering number,” he said. “Nitrous oxide is a really nasty agent to be releasing on a global scale.”
Lancaster added that nitrous oxide is photochemically reactive and can form free radicals – ozone-depleting agents – which aggravates the issue of blanketing Earth’s atmosphere with more gas and raising the globe’s temperature. “In addition to its role as a greenhouse gas cloak, it’s removing our protective shield,” Lancaster said.
The United States is among the world leaders in importing nitrogen fertilizer, according to the U.S. Department of Agriculture’s Economic Research Service. The Food and Agriculture Organization of the United Nations noted that the world’s nitrogen fertilizer demand was projected to be 116 million tons for this past agricultural season.
“For the world, I realize that we are trying to feed more people and that means more fertilizer – and that means more nitrous oxide,” said Lancaster, who noted that about 30 percent of nitrous oxide emissions come from agriculture and its accompanying land use.
To reduce the negative impact of nitrogen, farmers already use nitrification inhibitors.
Said Lancaster: “While it will be challenging to develop ways to stop this process, now we have pinpointed one biochemical step leading to nitrous oxide production. Future work may lead to inhibitors, molecules that can deactivate or neutralize this bacterial enzyme. Alternatively, we may just use this new information to develop better strategies for nitrogen management.”
The Department of Energy Office of Science and the National Institutes of Health supported the research.
Source: Cornell Chronicle
Cornell researchers have discovered a biological mechanism that helps convert nitrogen-based fertilizer into nitrous oxide, an ozone-depleting greenhouse gas. The paper was published online Nov. 17 in the Proceedings of the National Academy of Sciences.
“The first key to plugging a leak is finding the leak,” said Kyle Lancaster, assistant professor of chemistry and chemical biology, and senior author on the research. “We now know the key to the leak and what’s leading to it. Nitrous oxide is becoming quite significant in the atmosphere, as there has been a 120 percent increase of nitrous oxide in our atmosphere since pre-industrial times.”
Lancaster, along with postdoctoral researcher Jonathan D. Caranto and chemistry doctoral candidate Avery C. Vilbert, showed that an enzyme made by the ammonia oxidizing bacterium Nitrosomonas europaea, cytochrome P460, produces nitrous oxide after the organism turns ammonia into an intermediate metabolite called hydroxylamine.
N. europaea and similar “ammonia-oxidizing bacteria” use hydroxylamine as their fuel source, but too much hydroxylamine can be harmful – and the resulting production of nitrous oxide is a chemical coping strategy.
Lancaster and his colleagues hypothesize that when ammonia-oxidizing bacteria are exposed to high levels of nitrogen compounds, such as in crop fields or wastewater treatment plants, then nitrous oxide production via cytochrome P460 will ramp up.
In the atmosphere, greenhouse gases are a soup of many species, and Lancaster explained that nitrous oxide has 300 times the potency of carbon dioxide. “That’s a staggering number,” he said. “Nitrous oxide is a really nasty agent to be releasing on a global scale.”
Lancaster added that nitrous oxide is photochemically reactive and can form free radicals – ozone-depleting agents – which aggravates the issue of blanketing Earth’s atmosphere with more gas and raising the globe’s temperature. “In addition to its role as a greenhouse gas cloak, it’s removing our protective shield,” Lancaster said.
The United States is among the world leaders in importing nitrogen fertilizer, according to the U.S. Department of Agriculture’s Economic Research Service. The Food and Agriculture Organization of the United Nations noted that the world’s nitrogen fertilizer demand was projected to be 116 million tons for this past agricultural season.
“For the world, I realize that we are trying to feed more people and that means more fertilizer – and that means more nitrous oxide,” said Lancaster, who noted that about 30 percent of nitrous oxide emissions come from agriculture and its accompanying land use.
To reduce the negative impact of nitrogen, farmers already use nitrification inhibitors.
Said Lancaster: “While it will be challenging to develop ways to stop this process, now we have pinpointed one biochemical step leading to nitrous oxide production. Future work may lead to inhibitors, molecules that can deactivate or neutralize this bacterial enzyme. Alternatively, we may just use this new information to develop better strategies for nitrogen management.”
The Department of Energy Office of Science and the National Institutes of Health supported the research.
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