> Powerboat-World.com
 
 
News Home Video Gallery Newsletters FishingBoating Features Photo Gallery Sail-World Australia Australian Cruising
MarineBusiness-World

 

Sail-World.com : ‘Hot-Bunking’ bacterium recycles iron to boost ocean metabolism

‘Hot-Bunking’ bacterium recycles iron to boost ocean metabolism

'Got iron? It’s an essential nutrient for living things, but it’s scarce in the ocean. Scientists have found that a key marine bacterium, Crocosphaera watsonii, may have evolved a remarkable biochemical way to recycle iron for dual metabolic activities. - Woods Hole Oceanographic Institution'    Jack Cook, Woods Hole Oceanographic Institution

Woods Hole Oceanographic Institution found that in the vast ocean where an essential nutrient—iron—is scarce, a marine bacterium that launches the ocean food web survives by using a remarkable biochemical trick: It recycles iron.

By day, it uses iron in enzymes for photosynthesis to make carbohydrates; then by night, it appears to reuse the same iron in different enzymes to produce organic nitrogen for proteins.

The bacterium, Crocosphaera watsonii, is one of the few marine microbes that can convert nitrogen gas into organic nitrogen, which (just as it does on land) acts as fertilizer to stimulate plant growth in the ocean. So the ocean’s productivity is limited by nitrogen, which in turn is limited by scanty supplies of iron for the enzymes needed to make organic nitrogen.

This newfound capacity to conserve precious iron and use it in day-night shifts to satisfy two different metabolic demands reveals a surprising key to life on our planet, say scientists at Woods Hole Oceanographic Institution (WHOI) and Massachusetts Institute of Technology (MIT). They reported their findings Jan. 10 in the Proceedings of the National Academy of Sciences.

The scientists call the strategy 'hot bunking,' referring to ships that sail with fewer bunks than sailors on board. The bunks are kept continuously hot, as sailors finishing night shifts hop into bunks newly emptied by sailors arising for day shifts.

Crocosphaera uses iron-containing nitrogenase enzymes to convert dissolved nitrogen gas into organic nitrogen (a process called nitrogen 'fixing'). As the sun comes up, the bacterium breaks down these enzymes, releasing iron that can be used to make photosynthetic enzymes needed to convert dissolved carbon dioxide into carbohydrates. When the sun goes down, many of the photosynthetic enzymes are broken down, releasing the iron again to be recycled into nitrogenase.

Crocosphaera belongs to a subgroup of bacteria called cyanobacteria. 'They have a bit of a Dr. Jekyll and Mr. Hyde lifestyle: photosynthetic by day and nitrogen-fixing by night,' said Mak Saito, a WHOI biogeochemist and lead author of the PNAS paper. Scientists previously knew cyanobacteria had this unusual dual-metabolic capacity, but they did not know how they could accomplish it with meager iron supplies.

The bacterium pays a price in energy needed to destroy and rebuild enzymes each day, but it’s worth it to maximize the use of scarce iron. The scientists estimate that by using the hot bunking strategy, the organism can survive with about 40 percent less iron than it would otherwise need. It allows Crocosphaera to thrive and produce life-sustaining organic nitrogen in iron-poor waters that would otherwise be less productive.

The surprising abundance of cyanobacteria in the ocean was discovered in the 1970s by WHOI microbiologist Stanley Watson and his colleagues Frederica Valois and John Waterbury and, who later continued their pioneering research to elucidate cyanobacteria’s critical ecological roles for the ocean and the planet. Crocosphaera watsonii is named after the late Dr. Watson.

Cyanobacteria have been notoriously difficult to culture in the laboratory. At WHOI, Waterbury, Valois and colleagues established methods to culture cyanobacteria routinely and reliably, and they maintain a collection of cyanobacteria cells in a new building called the Stanley W. Watson Laboratory. The collection is a sort of lending library of cells that provide cultures for scientists all over the world to study, including new generations of WHOI scientists working in the Watson Lab: Saito, graduate student Erin Bertrand, and lab associates Vladimir Bulygin and Dawn Moran.

They applied new biomedical research techniques to the study of the ocean: proteomics. As genomics studies the genes in an organism (its genome), proteomics studies the proteins made from instructions encoded in genes (its proteome).

'We wanted to know not only what could potentially be made from Crocosphaera’s genome, but also what proteins Crocosphaera actually did make,' Saito said.

A key part of the technique involves using mass spectrometers that distinguish and measure the various proteins in an organism by the infinitesimal differences in their masses. The researchers measured the inventory of iron-containing proteins during periods of dark and light. Nitrogen-fixing enzymes were largely absent during the day and present at night; iron-containing photosynthetic enzymes decreased during dark periods and reappeared during light periods. Thus, at any time of day, Crocsophaera required only about half the iron it would need if it maintained both sets of enzymes throughout the day.

To explore the implications of Crocosphaera’s hot bunking ability, scientists at MIT—Stephanie Dutkiewicz, Fanny Monteiro and Mick Follows—used a numerical model that simulates global ocean circulation, biochemistry, and ecosystem dynamics. The model showed that Crocosphaera’s ability to reduce its iron requirements allowed it to inhabit ocean regions with low levels of iron. It also allowed the same iron supply to support more growth of the cyanobacteria and more nitrogen fixation that supports other marine life higher up on the food chain.

http://www.whoi.edu/




by Woods Hole Oceanographic Institution

  

Click on the FB Like link to post this story to your FB wall

http://www.powerboat-world.com/index.cfm?nid=79051

8:11 AM Tue 11 Jan 2011 GMT






Click here for printer friendly version
Click here to send us feedback or comments about this story.

Click for further information on
Environment and the ocean

Related News Stories:

27 Nov 2013  World Oceans Day appeals for funds
16 Nov 2013  Gigantic iceberg sails north from the Antarctic
09 Nov 2013  Sailing and swimming with manatees - Oceans Watch Essay
01 Nov 2013  OceansWatch: cruising sailors give something back in the South Pacific
23 Oct 2013  'The Ocean is Broken' - without fish, there can be no birds
13 Oct 2013  PlanetSolar reaches Paris after successful ocean study
02 Oct 2013  Monaco Yacht Show goes Green
07 Sep 2013  Great Pacific Garbage Patch - the real story
03 Sep 2013  World's largest solar yacht drops anchor after marine science quest
25 Aug 2013  Boat owners: cover vessels to deter seagulls
MORE STORIES ...

Power Boat News























Yamaha inspires students to succeed by Yamaha Motor Australia,








Swan celebrates sales success *Feature by Jeni Bone,




Polar research: Six priorities for Antarctic science by Mahlon C. Kennicutt II and colleagues,


Stealth i14 out of China by Neil Patchett,






























2014 Auckland on the Water Boatshow - Huge prize packs up for grabs
4X4 Outdoors Show and Fishing and Boating Expo wows water lovers
John Wilson has sights set on second P1 SuperStock title
Torquay Grand Prix - Pertemps tops table on penultimate day
Plain sailing for yachts with river cargo ship ban in Shanghai
Dangerous conditions for boaters from this afternoon
Sydney Int'l Boat Show - Stellar results for Multihull Solutions
NSW Environment Minister awards 'Fish Friendly' Marina Accreditations
Refurbished Protector project 'better than buying new'
Gold Coast International Marine Expo - High-Diver Steve Black is back
4x4 Outdoors Show, Fishing and Boating Expo - Campfire cooking corner
See the heat with FLIR ONE *Feature
John Temple to retire, Will Sangster appointed General Manager
Multihull Central launches Aquila range at SIBS *Feature
If all else fails read the instructions!!
If all else fails read the instructions!!
Sun shines on recreational boating at Sydney International Boat Show
Phuket Yacht Show: new kid on the block taking on PIMEX? *Feature
2014 Offshore Superboat Championships - The boats are back!
Sydney International Boat Show - Days 3 & 4 *Feature
Kirby Marine launch 13metre Naiad Tender   
Shellfish reefs in Port Phillip Bay to be rejuvenated   
2014 Brisbane Boat Show - What's your trailer boat worth?   
Custom exhaust system solves buoyancy problem   
Sydney International Boat Show - Day 2 *Feature   
Marine Rescue volunteers celebrate new unit and $120,000 vessel   
Sydney International Boat Show - images from Day 1 *Feature   
Pantaenius Insurance - being seen in yellow, green and orange *Feature   
Sydney International Boat Show begins!   
Sydney International Boat Show - Changed conditions on Sydney Harbour   
Fraser Island annual fishing closure starts August 1   
Mildura boaters reminded Murray River will be low until mid August   
Gold Coast Broadwater no closer to welcoming supermaxis *Feature   
Sydney International Boat Show - all systems go!   
UK superyacht industry on the rise   
EOMAP modelling shows what's under our water   
Great Barrier Reef in a bad state, and getting worse   
Gold Coast International Marine Expo - Organisers add extra sites   
Series Point’s Championship - Formula Two team secures a second place   
Marine Rescue volunteers called to rescue second vessel out of fuel   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png   http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW PBW
LocalAds   DE  ES  FR  IT