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Thread: B12 is also an essential vitamin for marine life

  1. #1
    Ex-admin Korn's Avatar
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    Default B12 is also an essential vitamin for marine life

    B12 Is Also An Essential Vitamin For Marine Life

    A few, short excerpts from Science Daily:
    B12—an essential vitamin for land-dwelling animals, including humans—also turns out to be an essential ingredient for growing marine plants that are critical to the ocean food web and Earth’s climate, scientists have found.

    he presence or absence of B12 in the ocean plays a vital and previously overlooked role in determining where, how much, and what kinds of microscopic algae (called phytoplankton) will bloom in the sea, according to a study published in the May issue of the journal Limnology and Oceanography.
    These photosynthesizing plants, in turn, have a critical impact on Earth’s climate: They draw huge amounts of carbon dioxide, a greenhouse gas, from the air, incorporating carbon into their bodies. When they die or are eaten, carbon is transferred to the ocean depths, where it cannot re-enter the atmosphere.
    B12 contains the metal cobalt and can be synthesized only by certain singled-celled bacteria and archaea. Humans, animals, and many algae require B12 to manufacture essential proteins, but they cannot make it and must either acquire it from the environment or eat food that contains B12, said the study’s lead authors, Erin Bertrand and Mak Saito. The two biogeochemists at the Woods Hole Oceanographic Institution wondered whether the vitamin was also important in the ocean, where B12 and cobalt are both found in exceedingly low concentrations.
    [...]
    In a symbiotic relationship, the algae get their required vitamin and the bacteria get a steady supply of carbon made by the plants. When Phaeocystis dies off and the bacteria are eaten or decomposed, B12 is released once again to the ocean and is available to be used by diatoms.
    [...]
    Any disruption in the timing or abundances of these microbial populations has ramifications on the ecosystem and the climate, the scientists said.
    [...]
    Any disruption in the timing or abundances of these microbial populations has ramifications on the ecosystem and the climate, the scientists said. For example, Phaeocystis antarctica in the Ross Sea takes up more carbon dioxide than diatoms, so if the marine community shifts to diatoms, the Ross Sea would likely remove less carbon dioxide from the atmosphere. Unlike diatoms, Phaeocystis also produce a compound called dimethylsulfioniopriopionate, or DMSP, which is released into the air and helps produce clouds that block solar radiation.
    Polar oceans do not have large bacterial populations to produce B12, making the vitamin a critical factor influencing the food web, the cycling of carbon in the ocean, and the climate, Bertrand and Saito said. At the same time, climate changes could affect the availability of B12 by causing changes in ocean temperatures, bacterial populations, and other factors. The ozone hole produced in the austral spring above Antarctica could also induce a cascade of effects by allowing more penetration of ultraviolet radiation that is known to degrade B12, they said.


    Erin Bertrand (right) and Mak Saito, biogeochemists at Woods Hole Oceanographic Insitution, have found evidence that B12, an essential vitamin for people, also plays a critical role in ocean food web. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)






    [My comment: Since the B12 found in ocean water both stimulates growth and has an 'essential' function and since the B12 is described as 'B12 is released once again to the ocean and is available to be used by diatoms', this sounds like 'bioavailable', active B12 and not inactive B12 analogues to me - at least to marine life. Korn.]

  2. #2
    Ex-admin Korn's Avatar
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    Default Re: B12 is also an essential vitamin for marine life

    Algae acquire vitamin B12 through a symbiotic relationship with bacteria.

    Algae acquire vitamin B12 through a symbiotic relationship with bacteria.

    Croft MT, Lawrence AD, Raux-Deery E, Warren MJ, Smith AG.
    Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
    Vitamin B12 (cobalamin) was identified nearly 80 years ago as the anti-pernicious anaemia factor in liver, and its importance in human health and disease has resulted in much work on its uptake, cellular transport and utilization. Plants do not contain cobalamin because they have no cobalamin-dependent enzymes. Deficiencies are therefore common in strict vegetarians, and in the elderly, who are susceptible to an autoimmune disorder that prevents its efficient uptake. In contrast, many algae are rich in vitamin B12, with some species, such as Porphyra yezoensis (Nori), containing as much cobalamin as liver. Despite this, the role of the cofactor in algal metabolism remains unknown, as does the source of the vitamin for these organisms. A survey of 326 algal species revealed that 171 species require exogenous vitamin B12 for growth, implying that more than half of the algal kingdom are cobalamin auxotrophs. Here we show that the role of vitamin B12 in algal metabolism is primarily as a cofactor for vitamin B12-dependent methionine synthase, and that cobalamin auxotrophy has arisen numerous times throughout evolution, probably owing to the loss of the vitamin B12-independent form of the enzyme. The source of cobalamin seems to be bacteria, indicating an important and unsuspected symbiosis.
    PMID: 16267554 [PubMed - indexed for MEDLINE]

    Since 171 out of 326 algal species require external vitamin B12 for growth, there must be a lot of B12 in the ocean. Maybe people who claim that B12 can only be found in animal products must consider some kind of beast... Maybe they've heard Graham Greene state the ocean is an animal, 'passive and ominous in a cage', 'waiting to show what it can do'?

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