@article{fdi:010081605,
  title = {{V}itamin {B}-12 excretion by cultures of the marine cyanobacteria {C}rocosphaera and {S}ynechococcus},
  author = {{B}onnet, {S}ophie and {W}ebb, {E}. {A}. and {P}anzeca, {C}. and {K}arl, {D}. {M}. and {C}apone, {D}. {G}. and {S}anudo-{W}ilhelmy, {S}. {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}xenic cultures of the {N}-2-fixing marine cyanobacterium {C}rocosphaera watsonii exhibit very high {B}-12 excretion rates (up to 40 times higher per cell), compared to the smaller non-{N}-2-fixing strain of marine {S}ynechococcus. {T}he effect of {N} availability on vitamin synthesis is also evident in the non-diazotrophic strain, as they release five times more {B}-12 under {N}-replete conditions relative to {N}-limiting conditions, although this value is still an order of magnitude smaller than the amount produced by the diazotroph. {T}he cyanobacterial contribution to the oceanic {B}-12 supply may be similar to 50 times higher than the contribution of heterotrophic bacteria. {O}ceanic cyanobacteria do not compete for exogenous {B}-12 with other prokaryotes and eukaryotes, but instead are obligate producers, thereby defining a unique dual ecological role for {N}-2-fixing cyanobacteria in the oligotrophic ocean. {T}hey provide both a source of "new' bioavailable nitrogen and the {B}-12 needed to support the growth of larger auxotrophic eukaryotic phytoplankton important for the biological carbon pump.},
  keywords = {},
  booktitle = {},
  journal = {{L}imnology and {O}ceanography},
  volume = {55},
  numero = {5},
  pages = {1959--1964},
  ISSN = {0024-3590},
  year = {2010},
  DOI = {10.4319/lo.2010.55.5.1959},
  URL = {https://www.documentation.ird.fr/hor/fdi:010081605},
}