JPR Advance Access originally published online on January 19, 2007
Journal of Plankton Research 2007 29(2):107-113; doi:10.1093/plankt/fbm009
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
HORIZONS |
Vitamins, phytoplankton and bacteria: symbiosis or scavenging?
Scottish Association For Marine Science, Dunstaffnage Marine Research Laboratory, Oban, Argyll, PA37 1QA, Scotland
* Corresponding Author: m.droop{at}ukonline.co.uk
Received on July 19, 2006; accepted on December 14, 2006
 |
Abstract |
|---|
The conclusion that over 25% of global primary production depends on direct algal/bacterial symbiosis involving vitamin B12 [Croft et al., (2005) Algae acquire vitamin B12 through a symbiotic relationship with bacteria. Nature, 438, 90–93] is patently false, for it is based on a misconception of the probable level of the vitamin B12 requirement in marine pelagic algae. A review of the various published attempts at measuring this requirement 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. The levels measured are discussed in relation to method (batch or continuous culture) and protocols used. Requirement values considered by the author to be acceptable range from 0.1 to 0.3 pM for the vitamin growth saturation constant (KS) and from 30 to 100 µL algal biomass pmol–1 vitamin for the yield.
Communicating editor: K.J. Flynn
Written responses to this article should be submitted to Kevin Flynn at k.j.flynn{at}swansea.ac.uk within two months of publication. For further information, please see the Editorial ‘Horizons’ in Journal of Plankton Research, Volume 26, Number 3, Page 257.