Algae acquire vitamin B12 through a symbiotic relationship with bacteria

  title={Algae acquire vitamin B12 through a symbiotic relationship with bacteria},
  author={Martin Tom Croft and Andrew D. Lawrence and Evelyne Raux-Deery and Martin J. Warren and Alison G. Smith},
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… 
Microbiology: Algae and the vitamin mosaic
A survey of the vitamin B12 requirements of more than 300 microalgal species has produced a startling result: just under half of the algae have no requirement for the vitamin, and so are just like plants, but the rest of these supposedly autotrophic organisms require an external supply of theitamin.
Mutualistic interactions between vitamin B12 -dependent algae and heterotrophic bacteria exhibit regulation.
A system to study the interaction between algae and heterotrophic bacteria at the molecular level and the implications for the widespread distribution of cobalamin auxotrophy in the algal kingdom are established.
The role of B vitamins in marine biogeochemistry.
It is shown that vitamins originate from the activities of some bacteria and algae and that taxonomic changes observed in marine phytoplankton communities could be the result of their specific vitamin requirements and/or vitamin availability.
Vitamin B12 (Cobalamin) Biosynthesis in the Purple Bacteria
This chapter describes the aerobic pathway for cobalamin biosynthesis, a coenzyme that appears to be required for a number of cellular activities in the purple bacteria including the formation of the active photosynthetic apparatus.
Utilization of Cobalamin Is Ubiquitous in Early-Branching Fungal Phyla
The results indicate that cobalamin dependence was a widely distributed trait at least in Opisthokonta, across diverse microbial eukaryotes and likely in the LECA.
Vitamins, Phytoplankton and Bacteria: Symbiosis or Scavenging?
A review of the various published attempts at measuring this requirement of vitamin B 12 in marine pelagic algae suggests that it is likely to be so low that oceanic and coastal concentrations of the vitamin would usually be sufficient to sustain the populations that occur without the assistance of direct algal/bacterial symbiosis.
HORIZONS Vitamins, phytoplankton and bacteria: symbiosis or scavenging?
A review of the various published attempts at measuring this requirement of vitamin B12 in marine pelagic algae suggests that it is likely to be so low that oceanic and coastal concentrations of the vitamin would usually be sufficient to sustain the populations that occur without the assistance of direct algal/bacterial symbiosis.
Unraveling Vitamin B12-Responsive Gene Regulation in Algae1[W]
This work probes METE gene regulation by B12 and methionine/folate cycle metabolites in both marine and freshwater microalgal species and identifies a B12-responsive element of Chlamydomonas reinhardtii METE using a reporter gene approach.
Sharing Vitamin B12 between Bacteria and Microalgae Does Not Systematically Occur: Case Study of the Haptophyte Tisochrysis lutea
It is suggested that direct sharing of vitamin B12 is specific to each species pair and that algae in complex natural communities can acquire it indirectly by other mechanisms (e.g., after bacterial lysis).
Microalgal assimilation of vitamin B12 toward the production of a superfood.
An in-depth and timely overview on vitamin B 12 biosynthesis and the major advances on metabolic engineering for improved vitamin B12 production by probiotic bacteria and other microorganisms generally recognized as safe are provided.


Vitamin B12 deficiency as a worldwide problem.
Pernicious anemia is a common cause of megaloblastic anemia throughout the world and especially in persons of European or African descent. Dietary deficiency of vitamin B12 due to vegetarianism is
Salmonella typhimurium cobalamin (vitamin B12) biosynthetic genes: functional studies in S. typhimurium and Escherichia coli
The finding that S. typhimurium cbiL mutants are not complemented with the homologous Pseudomonas denitrificans gene lends further credence to the theory that cobalt is required at an early stage in the biosynthesis of cobalamins in S. Typhimurial.
The many faces of vitamin B12: catalysis by cobalamin-dependent enzymes.
Understanding of the reaction mechanisms of B12 enzymes has been greatly enhanced by the availability of large amounts of enzyme that have afforded detailed structure-function studies, and these recent advances are the subject of this review.
Folate/vitamin B12 inter-relationships.
Folate deficiency causes anaemia owing to impaired purine and pyrimidine biosynthesis. Vitamin B12 deficiency causes an identical anaemia owing to metabolic trapping of intracellular folate. Vitamin
The Genome of the Diatom Thalassiosira Pseudonana: Ecology, Evolution, and Metabolism
It is identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, use of a range of nitrogenous compounds, and a complete urea cycle, all attributes that allow diatoms to prosper in aquatic environments.
Comparison of cobalamin-independent and cobalamin-dependent methionine synthases from Escherichia coli: two solutions to the same chemical problem.
A rapid one-step purification of the recombinant cobalamin-independent methionine synthase (MetE) that yields homogeneous protein in high yield for mechanistic and structural studies and identifies a highly reactive thiol in MetE that is alkylated by chloromethyl ketones and by iodoacetamide.
Characterization of a Vitamin B12 Compound in the Edible Purple Laver, Porphyra yezoensis
The edible purple laver, Porphyra yezoensis, contained 51.49±1.51 μg of vitamin B12 compounds per 100 g dry weight of the laver (mean±SEM, n=4). A vitamin B12 compound was purified from the
Oligotrophic Bacteria Enhance Algal Growth under Iron-Deficient Conditions
A Halomonas sp., a marine halophilic and oligotrophic bacterium, was grown on exudates of Dunaliella bardawil. The bacteria increased the solubility of Fe, thereby enhancing its availability to the