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Scientists identify key factor that controls ocean nitrogen availability

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Oceanic oxygen minimum zones. Depicted is the oxygen concentration at 300 meter water depth. Around 30- 50% of global marine N-loss takes place in these areas, which represent only ca. 0.1% of the ocean s volume. Credit: Image is modified after World Ocean Atlas 2009 nodc.noaa.gov

(Phys.org)During an expedition to the South Pacific Ocean, scientists from the Max Planck Institute for Marine Microbiology in Bremen, along with their colleagues from the GEOMAR and Christian-Albrechts University in Kiel, discovered that organic matter derived from decaying algae regulates nitrogen loss from the Ocean's oxygen minimum zones. They published their discovery in the renowned scientific journal Nature Geoscience.

One of the central aims of today's marine research is to better predict the response of our Ocean to global warming and human activity in general. Understanding of the oceanic nitrogen cycle is of key importance in this effort as nitrogen is the limiting nutrient for life in the Ocean. Its bio-available form (so-called fixed nitrogen, such as ammonium) is produced biologically from nitrogen gas by bacteria or is transported to the ocean as dust or river run-off. However, due to the activity of marine microorganisms growing in virtually oxygen free conditions, this fixed nitrogen is rapidly converted back to nitrogen gas, which escapes from the Ocean to the atmosphere. There are two processes, which are mainly responsible for this nitrogen loss: denitrification and anammox (anaerobic oxidation of ammonium with nitrite), both performed by anaerobic bacteria.

Up to 40% of global oceanic nitrogen loss occurs in so-called oxygen minimum zones (OMZ), which are areas with low to non-measurable oxygen concentrations. "The eastern tropical South Pacific OMZ is one of the largest OMZs in the world," explains Tim Kalvelage from the Max Planck Institute for Marine Microbiology, the first author of this study. "We assumed that if we could identify and constrain the parameters that regulate N loss from this OMZ, we could better predict the N loss from all OMZs, and possibly from the Ocean, as well." Professor Andreas Oschlies of GEOMAR Kiel and speaker of the Collaborative Research Centre SFB 754 adds: "This research is fundamental for improving our current biogeochemical models that, so far, cannot reliably reproduce the patterns of N loss that we measure."

As a part of the German National Research Foundation (DFG) funded SFB 754 a series of expeditions onboard of the research ship Meteor in 2008/2009 were specifically dedicated to collect samples from the South Pacific OMZ. Further analyses and measurements followed in the laboratories of the Max Planck Institute for Marine Microbiology in Bremen, GEOMAR Helmholtz Centre for Ocean Research and Institute for General Microbiology in Kiel. The results provide a detailed overview of nutrient distributions, rates of N loss processes and abundances and identity of bacteria in the South Pacific OMZ. Furthermore, models were employed to calculate the amount of algal biomass that is exported from the surface to the deeper OMZ waters. This large-scale study resulted in the so far most comprehensive nitrogen budget for an oceanic OMZ. The results were surprising: "We saw that the rates of nitrogen loss, mainly due to anammox, strongly correlated with the export of organic matter," explains Tim Kalvelage. "This was unexpected because anammox bacteria do not grow on organic matter but use ammonium and CO2." The scientists found out that the N-rich organic matter most likely serves as a key source of ammonium for the anammox reaction.

Professor Marcel Kuypers concludes: "Our results will help to more realistically estimate the short- and long-term impacts of human-induced ocean de-oxygenation and changing productivity on nitrogen cycling in the OMZs, as well as the rest of the Ocean. This is critical to estimate how much CO2 can be taken up by the Ocean in the future."

More information: Nitrogen cycling driven by organic matter export in the South Pacific oxygen minimum zone, Tim Kalvelage, Gaute Lavik, Phyllis Lam, Sergio Contreras, Lionel Arteaga, Carolin R. Lscher, Andreas Oschlies, Aurlien Paulmier, Lothar Stramma and Marcel M. M. Kuypers, Nature Geoscience (2013) doi:10.1038/NGEO1739

Journal reference: Nature Geoscience

Provided by Max Planck Society

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Scientists identify key factor that controls ocean nitrogen availability

How the Ocean loses nitrogen: Scientists identify key factor that controls nitrogen availability in the Ocean

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Feb. 24, 2013 During an expedition to the South Pacific Ocean, scientists from the Max Planck Institute for Marine Microbiology in Bremen, along with their colleagues from the GEOMAR and Christian-Albrechts University in Kiel, discovered that organic matter derived from decaying algae regulates nitrogen loss from the Ocean's oxygen minimum zones.

They published their discovery in the scientific journal Nature Geoscience.

One of the central aims of today's marine research is to better predict the response of our Ocean to global warming and human activity in general. Understanding of the oceanic nitrogen cycle is of key importance in this effort as nitrogen is the limiting nutrient for life in the Ocean. Its bio-available form (so-called fixed nitrogen, such as ammonium) is produced biologically from nitrogen gas by bacteria or is transported to the ocean as dust or river run-off. However, due to the activity of marine microorganisms growing in virtually oxygen free conditions, this fixed nitrogen is rapidly converted back to nitrogen gas, which escapes from the Ocean to the atmosphere. There are two processes, which are mainly responsible for this nitrogen loss: denitrification and anammox (anaerobic oxidation of ammonium with nitrite), both performed by anaerobic bacteria.

Up to 40% of global oceanic nitrogen loss occurs in so-called oxygen minimum zones (OMZ), which are areas with low to non-measurable oxygen concentrations. "The eastern tropical South Pacific OMZ is one of the largest OMZs in the world," explains Tim Kalvelage from the Max Planck Institute for Marine Microbiology, the first author of this study. "We assumed that if we could identify and constrain the parameters that regulate N loss from this OMZ, we could better predict the N loss from all OMZs, and possibly from the Ocean, as well." Professor Andreas Oschlies of GEOMAR Kiel and speaker of the Collaborative Research Centre SFB 754 adds: "This research is fundamental for improving our current biogeochemical models that, so far, cannot reliably reproduce the patterns of N loss that we measure."

As a part of the German National Research Foundation (DFG) funded SFB 754 a series of expeditions onboard of the research ship Meteor in 2008/2009 were specifically dedicated to collect samples from the South Pacific OMZ. Further analyses and measurements followed in the laboratories of the Max Planck Institute for Marine Microbiology in Bremen, GEOMAR Helmholtz Centre for Ocean Research and Institute for General Microbiology in Kiel. The results provide a detailed overview of nutrient distributions, rates of N loss processes and abundances and identity of bacteria in the South Pacific OMZ. Furthermore, models were employed to calculate the amount of algal biomass that is exported from the surface to the deeper OMZ waters. This large-scale study resulted in the so far most comprehensive nitrogen budget for an oceanic OMZ. The results were surprising: "We saw that the rates of nitrogen loss, mainly due to anammox, strongly correlated with the export of organic matter," explains Tim Kalvelage. "This was unexpected because anammox bacteria do not grow on organic matter but use ammonium and CO2." The scientists found out that the N-rich organic matter most likely serves as a key source of ammonium for the anammox reaction.

Professor Marcel Kuypers concludes: "Our results will help to more realistically estimate the short- and long-term impacts of human-induced ocean de-oxygenation and changing productivity on nitrogen cycling in the OMZs, as well as the rest of the Ocean. This is critical to estimate how much CO2 can be taken up by the Ocean in the future."

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The above story is reprinted from materials provided by Max-Planck-Institut fr marine Mikrobiologie, via AlphaGalileo.

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How the Ocean loses nitrogen: Scientists identify key factor that controls nitrogen availability in the Ocean

Dimensionality Reduction From Several Angles – Video

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Dimensionality Reduction From Several Angles
Tamara Munzner, Professor, Department of Computer Science, University of British Columbia Presents... Dimensionality Reduction From Several Angles I will present five past and current projects that attack the problem of dimensionality reduction (DR) from quite different methodological angles. Two projects nicely fit into the usual mold of technique-driven work on algorithms for DR. Glimmer is a multilevel multidimensional scaling (MDS) algorithm that exploits the GPU. Glint is a new MDS framework that achieves high performance on costly distance functions. In contrast, the DimStiller project is a foray into systems rather than algorithms, built around the idea of "DR for the rest of us". It is a toolkit for DR that provides local and global guidance to users who may not be experts in the mathematics of high-dimensional data analysis. A third kind of project combines evaluation and the creation of taxonomies. Our recent taxonomy of visual cluster separation factors arose from the systematic qualitative examination of over 800 scatterplots of dimensionally reduced data, and includes an analysis of the reasons for failure of previous cluster separation metrics. I will also discuss the current work of a task taxonomy that is grounded in a two-year qualitative study of high-dimensional data analysts in many domains, to discover how the use of DR "in the wild" does and does not match up with the assumptions that underlie previous algorithmic work. Tamara Munzner is a professor ...

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Dimensionality Reduction From Several Angles - Video

Writing an Application Letter for a Faculty Position – LSU Health PDA – Video

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Writing an Application Letter for a Faculty Position - LSU Health PDA
LSU Health PDA workshop on writing an application letter for a faculty position, February 21, 2013. Speakers: Dr. Felicity Gavins, Assistant Professor, Department of Molecular and Cellular Physiology, and Dr. Jason Bodily, Assistant Professor, Department of Microbiology and immunology, LSU Health, Shreveport, LA. Contact us at: lsuhealth.pda@gmail.com http://www.facebook.com/LSUHealthPDA http://www.linkedin.com

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Writing an Application Letter for a Faculty Position - LSU Health PDA - Video

In Motion Broadcast VI – Synthetic Biology [Part 1] – Video

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In Motion Broadcast VI - Synthetic Biology [Part 1]
This Video is Part 1 of 2 In Motion Broadcast Part 2 - youtu.be We present and explore the science and ethics of creating new forms of life. Synthetic Biology -- This broad redefinition and expansion of biotechnology, holds the ultimate goals of being able to design and build engineered biological systems, which could produce energy, food, or to maintain and enhance human health or the environment. Episode VI features genetic engineer Dr. Drew Endy and microbiologist Andrew Hessel, the author of #39;Forbidden Gates #39;, Thomas Horn and more -- as we prepare for humankind to take over the responsibilities of Creation. Featured Sources Fidelity Investments: Thinking Big with Synthetic Biology Published on Apr 27, 2012 In this presentation, Fidelity analyst Robert Chan gives an broad introduction to synthetic biology. -- "Goats are making silk stronger than steel, and we see opportunity". Bride8 Synthetic Biology Explained Uploaded on Aug 9, 2011 Written by James Hutson, this source is used as the Intro to Episode VI and throughout -- to explain and support the views of other included sources. Dr. Andrew David Endy Interview by Dr. Quinn Norton Community Radio Assistant Professor of Bioengineering, Stanford University, Dr. Endy speaks about the many facets of synthetic biology- the inheritor of genetic engineering. archive.org Thomas Horn interview with #39;Hildi #39; First Hour of One Cell One Light with Dr. Hildegarde Staninger Interview -- 12/14/11, Author Thomas Horn brings to light ...

By: Tom Hickson

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In Motion Broadcast VI - Synthetic Biology [Part 1] - Video

In Motion Broadcast VI – Synthetic Biology [Part 2] – Video

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In Motion Broadcast VI - Synthetic Biology [Part 2]
This Video is Part 2 of 2 In Motion Broadcast Part 1 - youtu.be We present and explore the science and ethics of creating new forms of life. Synthetic Biology -- This broad redefinition and expansion of biotechnology, holds the ultimate goals of being able to design and build engineered biological systems, which could produce energy, food, or to maintain and enhance human health or the environment. Episode VI features genetic engineer Dr. Drew Endy and microbiologist Andrew Hessel, the author of #39;Forbidden Gates #39;, Thomas Horn and more -- as we prepare for humankind to take over the responsibilities of Creation. Featured Sources Fidelity Investments: Thinking Big with Synthetic Biology Published on Apr 27, 2012 In this presentation, Fidelity analyst Robert Chan gives an broad introduction to synthetic biology. -- "Goats are making silk stronger than steel, and we see opportunity". Bride8 Synthetic Biology Explained Uploaded on Aug 9, 2011 Written by James Hutson, this source is used as the Intro to Episode VI and throughout -- to explain and support the views of other included sources. Dr. Andrew David Endy Interview by Dr. Quinn Norton Community Radio Assistant Professor of Bioengineering, Stanford University, Dr. Endy speaks about the many facets of synthetic biology- the inheritor of genetic engineering. archive.org Thomas Horn interview with #39;Hildi #39; First Hour of One Cell One Light with Dr. Hildegarde Staninger Interview -- 12/14/11, Author Thomas Horn brings to light ...

By: Tom Hickson

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In Motion Broadcast VI - Synthetic Biology [Part 2] - Video

How to make awesome gourmet sauerkraut at home! – Video

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How to make awesome gourmet sauerkraut at home!
Credits go to Jake (RawUtah) and Patchie for introducing me to fermentation! I show you how to make awesome gourmet sauerkraut at home! The ingredients I use is: A head and a half of Red Cabbage, 1/2 a head of Green Cabbage, 1 cup of Celery, 1/2 cup or so of Red Onion, a whole cup or more of Cilantro, 4 tablespoons or more of Sea Vegetables, 1/4 to 1/2 cup of Fresh Ginger, 2 tablespoons or so of Celery Seeds, 3 tablespoons of Fennel Seeds and 2 tablespoons of Turmeric *use fresh if you have some* I used them in a powdered form. And 4-5 tablespoons or so Sea Salt! Do not use iodine as it inhibits the fermentation process! This is a variation of their own kraut called Killa Kraut! Check out their videos below!!! Pure Joy Town Fermentation Series: KILLA Kraut http://www.youtube.com Pure Joy Town: KERMIT THEE KRAUT (Make your own sauerkraut!) http://www.youtube.com Upcoming Free Fermentation Classes by Pure Joy Town http://www.purejoytown.com Enjoy! --------------------------------------------------------------------------------------------------- SOME INTERESTING HISTORY OF SAUERKRAUT: The fermentation process used to make sauerkraut was probably first developed centuries ago simply as a means of preserving vegetables for easy consumption throughout the winter. The health benefits derived from pickling vegetables were already well-known to early civilizations. Historical evidence suggests laborers on the Great Wall of China consumed a version of the pickled cabbage dish 2000 years ago ...

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How to make awesome gourmet sauerkraut at home! - Video

40 Days Of DIY Microbiology Part Four – Video

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40 Days Of DIY Microbiology Part Four
This time around, it #39;s pure observation over several hours of time on day one of the sealed slide. The slide was created on October 10th, 2013, as a sealed wet mount intended for very long duration observation totalling weeks or even months of time. This was just day one. There #39;s lots more footage - and discoveries - to come! Rick NR417

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40 Days Of DIY Microbiology Part Four - Video

EPR Interviews Lonza at PDA 7th Annual Pharmaceutical Microbiology Conference – Video

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EPR Interviews Lonza at PDA 7th Annual Pharmaceutical Microbiology Conference
Lakiya Wimbish, Lonza, discusses Lonza #39;s Pyrogene trade; Recombinant Factor C (rFC) Assay with regard to Endotoxin Detection. Freddy White, Director, European Pharmaceutical Review interviews Lakiya Wimbish, Product Manager, Lonza at PDA 7th Annual Global Conference on Pharmaceutical Microbiology.

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Legionella colonies on agar plates – Video

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Legionella colonies on agar plates
Legionella are the causative agents of the Legionnaires #39; disease (lung infection). These bacteria are growing in water distribution systems and infection is produced by inhalation of contaminated aerosols. Fifty-eight different species have been described until Y2012 but 90% of infections are due to L. pneumophila. We thank Dr. Valeria Gaia (Cantonal Institute of Microbiology, Bellinzona, Switzerland, www4.ti.ch ) for some strains of Legionella presented in this video.

By: Jenni Bernard

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Legionella colonies on agar plates - Video

Why sourdough bread resists mold

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Public release date: 21-Feb-2013 [ | E-mail | Share ]

Contact: Jim Sliwa jsliwa@asmusa.org 202-942-9297 American Society for Microbiology

Sourdough bread resists mold, unlike conventionally leavened bread. Now Michael Gaenzle and colleagues of the University of Alberta, Edmonton, show why. During sourdough production, bacteria convert the linoleic acid in bread flour to a compound that has powerful antifungal activity. The research, which could improve the taste of bread, is published online ahead of print in the journal Applied and Environmental Microbiology.

The major benefits from the research are twofold: better tasting bread, says Gaenzle, because "preservatives can be eliminated from the recipes, and because sourdough bread has a more distinct and richer flavor compared to bread produced with yeast only;" and novel tools to control fungi in malting and plant production, via treatment of seeds with the anti-fungal fatty acids.

Genuine sourdough bread differs from ordinary bread in having an extra fermentation step, over and above yeast fermentation. This step is mediated by lactic acid bacteria, typically of the genus Lactobacillus, says Gaenzle.

In the study, "we offered linoleic acid to lactobacilli and screened for organisms producing potent antifungal activity," says Gaenzle. The investigators then fractionated the metabolites to isolate and identify compounds with antifungal activity. "The identification was a bottleneck in the research project," says Gaenzle. "In collaboration with analytical chemists, we had to develop novel methods for identifying the compounds."

L. hammesii produced substantial quantities of hydroxylated monounsaturated fatty acids which the researchers found strongly inhibited mold formation. A second antifungal fatty acid produced by cereal enzymes contributes to the antifungal activity of sourdough.

"The two compounds and their formation by cereal or microbial enzymes had been described previously, but their antifungal activity and their generation in food production was unknown," says Gaenzle. These new findings, he says, were "a step towards understanding how and why lactobacilli metabolize fatty acids. This could be useful in the long term to improve our understanding of the biology of these organisms."

###

A copy of the manuscript can be found online at http://bit.ly/asmtip0213a. Formal publication of the article is scheduled for the second March 2013 issue of Applied and Environmental Microbiology.

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Why sourdough bread resists mold

Rangoli Compititon at Dolpholphin PG College of Life Sciences – Video

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Rangoli Compititon at Dolpholphin PG College of Life Sciences
Dolphin (PG) College of Life Sciences Chunni Kalan, Distt. Fatehgarh Sahib organized one day event to celebrate National Voters Day on 13th February 2013. Poster making, Rangoli and Debate on the theme "Role of Youth in Indian Democracy" were the high lights of this function. All the students of M.Sc. Biotechnology, Medical Biotechnology Microbiology, Pharmaceutical Chemistry, Chemistry, Botany, Zoology, and B.Sc. Agriculture, Industrial Microbiology, Biotechnology actively participated. The winning team included.

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Rangoli Compititon at Dolpholphin PG College of Life Sciences - Video

USP: Microbiological Control of Compendial Articles – Video

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USP: Microbiological Control of Compendial Articles
James Akers, Ph.D., chair of the USP General Chapters mdash;Microbiology Expert Committee, discusses the upcoming workshop, "Microbiological Control of Compendial Articles," and its relevance to sterile and non-sterile pharmaceutical products. The USP work

By: PharmaSci

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USP: Microbiological Control of Compendial Articles - Video


  1. Microbiology