If you have ever wondered at the wonder of vitamins keep in mind that it’s not only humans who need them. Vitamins are essential micro-nutrients that are necessary for health of all forms of life. Now we know that the largest organisms on the planet, plankton blooms, are able to produce their own vitamins in more ways than one.
They are particularly adroit at making vital B-12 the shortage of which we know in our own lives results in pernicious anemia. Hmmm… pelagic ocean plankton blooms are by their very nature desperately short of iron and thus are perniciously anemic. Now we know they evolved a way to produce the very thing they need most to offset this condition. So cool!
University of Washington researchers used new tools to measure and track B-12 vitamins in the ocean. Once believed to be manufactured only by marine bacteria, the new results show that a whole different class of organism, archaea – picoplankton, can produce an abundant supply this essential vitamin. The results were presented Feb. 24 at the Ocean Sciences meeting in Honolulu.
“The dominant paradigm has been bacteria are out there, making B-12, but it turns out that one of the most common marine bacteria doesn’t make it,” said Anitra Ingalls, a UW associate professor of oceanography.
All marine animals, some marine bacteria and some tiny marine algae, or phytoplankton, need B-12, but only some microbes can produce the large, complex molecule. So like human vegetarians on land, marine organisms may be desperately in need of food that can help stave off vitamin deficiency.
“If only certain bacteria can make B vitamins, that can make B-12 a controlling factor in the environment. Is it present or not?” said Katherine Heal, a UW oceanography graduate student. “Studying the marine microbiome can help us understand what microbial communities could be supported where, and how that affects things like the ocean’s capacity to absorb atmospheric CO2.” The healthier the ocean the more CO2 its plankton can covert from its chemically deadly simple form into life itself.
The UW team is the first to show that marine archaea, a single-celled organism that evolved along a separate evolutionary path from bacteria and all other living things, are making B-12. These tiny plant-like life forms are known for finding a niche in unusual habitats like living inside hot springs and underwater volcanoes.
The Seattle team managed to grow a common type of open-ocean archaea in the lab, no mean feat, and show that it not only makes enough B-12 to support its own growth but that it also supplies extra to its environment.
“It’s hard to quantify their contribution,” Ingalls said. “This is a first glimpse at their potential to contribute to this pool of vitamins.”
Field experiments involved sampling seawater in Hood Canal, near Seattle, and in the Pacific Ocean hundreds of miles offshore. The results showed that B-12 was present in small amounts in all water samples. Concentrations were low enough in some places that vitamin deficiency among tiny marine algae, or phytoplankton, is likely.
“Having a very small amount doesn’t mean there’s a very small supply,” Ingalls said. “Low concentrations can indicate something that’s highly desirable to marine organisms.”
The next step, researchers said, is to connect different microbes’ activity with the production of B vitamins, to see which organisms are responsible where, and to look at how ocean vitamins affect the type and amount of phytoplankton growing in the water.
Recent sequencing of the genomes of marine microbes has revealed genetic pathways in bacteria and archaea for creating B vitamins, but just because the gene is there doesn’t mean it’s being used. Marine microbes often adapt their behavior depending on the environment. In the case of vitamins, some organisms make more B-12 if phytoplankton is nearby. By helping the phyto-plankton to grown they will benefit from its eventual demise and conversion into ocean compost which is their eventual food source.
The UW team hopes to learn which microbes are producing B-12 vitamins where, to better understand how the base of the marine food web works, how it might alter in a changing environment, how oceans might help regulate atmospheric carbon dioxide, and where marine animals could go to get a well-balanced diet.
“The public really has a very strange relationship to microorganisms,” Ingalls said. “People know they cause disease, so they want to kill them. But they’re also the only reason that we – or whales, fish or coral reefs – are alive.” Read more on the UW site.
An interesting question that the UW researchers might have in their data is whether there is significant substitution of iron for cobalt in the oceanic B-12 molecule.
On the other hand wind blown dust as the primary source of pelagic iron ordinarily contains trace cobalt along with it’s iron bearing hematite. That means a practical source of cobalt to make B-12 is certainly in Mother Natures evolutionary cookbook. No wonder dust in the wind is such a wondrous and vital ocean nutrient. Read about the Yin and Yang of dust here.