The thiamine (vitamin B1) content of phytoplankton is affected by temperature, photon density and salinity
(English)In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599Article in journal (Refereed) Submitted
Thiamine (vitamin B1) is produced by plants, algae and bacteria and must be acquired through the food web by higher trophic levels. In this study we investigate the biosynthesis of thiamine in six phytoplankton species belonging to five different phyla under different environmental conditions. The chlorophyte Dunaliella tertiolecta, the dinoflagellate Prorocentrum minimum and the prymnesiophyte Rhodomonas salina were found to be thiamine auxotrophs, while the cyanobacterium Nodularia spumigena and the diatoms Phaeodactylum tricornutum and Skeletonema costatum were capable of thiamine synthesis. Measured net thiamine production in the latter three species varied with temperature, photon density and salinity. These effects were different for the cyanobacterium and the diatoms and strongest for salinity. In N. spumigena, the total thiamine concentration increased threefold with increased salinity. P. tricornutum accumulated seven times more thiamine diphosphate when salinity was decreased. Temperature also had pronounced effects on thiamine concentration, while photon density only affected thiamine levels in combination with temperature. In N. spumigena and P. tricornutum, total thiamine levels increased with higher temperature. We demonstrate a high variability among phytoplankton species in thiamine biosynthesis, as well as in the level of thiamine production in response to environmental factors. Thus, regime shifts in phytoplankton community composition through large-scale environmental change can alter the vitamin B1 availability for higher trophic levels. This may have serious consequences for the access of zooplankton, fish, birds and mammals to this essential vitamin in changing ecosystems.
phytoplankton, thiamine, M74, Vitamin B1
IdentifiersURN: urn:nbn:se:uu:diva-130139OAI: oai:DiVA.org:uu-130139DiVA: diva2:346642