title: Selective silicate-directed motility in diatoms.
abstract: Diatoms are highly abundant unicellular algae that often dominate pelagic as well as benthic primary production in the oceans and inland waters. Being strictly dependent on silica to build their biomineralized cell walls, marine diatoms precipitate 240 × 10(12) mol Si per year, which makes them the major sink in the global Si cycle. Dissolved silicic acid (dSi) availability frequently limits diatom productivity and influences species composition of communities. We show that benthic diatoms selectively perceive and behaviourally react to gradients of dSi. Cell speed increases under dSi-limited conditions in a chemokinetic response and, if gradients of this resource are present, increased directionality of cell movement promotes chemotaxis. The ability to exploit local and short-lived dSi hotspots using a specific search behaviour likely contributes to micro-scale patch dynamics in biofilm communities. On a global scale this behaviour might affect sediment-water dSi fluxes and biogeochemical cycling.
authors: Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Department of Chemistry and Earth Sciences, Friedrich-Schiller-Universität Jena, Lessingstrasse 8, D-07743 Jena, Germany.|Max Planck Institute for Chemical Ecology, Max Planck Fellow, Hans-Knöll-Str. 8, D-07745 Jena, Germany.
authors: Karen Grace V
authors: KG
authors: Bondoc
authors: Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark, Charlottenlund Slot, Jægersborg Allé, DK-2920 Charlottenlund, Denmark.|Department of Biology, Aquatic Ecology Unit, Lund University, SE-22362 Lund, Sweden.
authors: Jan
authors: J
authors: Heuschele
authors: Laboratory of Protistology and Aquatic Ecology, Department of Biology, University Gent, Krijgslaan 281, S8, 9000 Gent, Belgium.|California State University, Department of Biology, 9001 Stockdale Hwy, Bakersfield, California 93311, USA.
authors: Jeroen
authors: J
authors: Gillard
authors: Laboratory of Protistology and Aquatic Ecology, Department of Biology, University Gent, Krijgslaan 281, S8, 9000 Gent, Belgium.
authors: Wim
authors: W
authors: Vyverman
authors: Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Department of Chemistry and Earth Sciences, Friedrich-Schiller-Universität Jena, Lessingstrasse 8, D-07743 Jena, Germany.|Max Planck Institute for Chemical Ecology, Max Planck Fellow, Hans-Knöll-Str. 8, D-07745 Jena, Germany.
authors: Georg
authors: G
authors: Pohnert