title: New insights into shear-sensitivity in dinoflagellate microalgae.
abstract: A modification of a flow contraction device was used to subject shear-sensitive microalgae to well-defined hydrodynamic forces. The aim of the study was to elucidate if the inhibition of shear-induced growth commonly observed in dinoflagellate microalgae is in effect due to cell fragility that results in cell breakage even at low levels of turbulence. The microalgae assayed did not show any cell breakage even at energy dissipation rates (EDR) around 10(12)Wm(-3), implausible in culture devices. Conversely, animal cells, tested for comparison purposes, showed high physical cell damage at average EDR levels of 10(7)Wm(-3). Besides, very short exposures to high levels of EDR promoted variations in the membrane fluidity of the microalgae assayed, which might trigger mechanosensory cellular mechanisms. Average EDR values of only about 4·10(5)Wm(-3) increased cell membrane fluidity in microalgae whereas, in animal cells, they did not.
authors.affiliation: Chemical Engineering Area, University of Almería, 04120 Almería, Spain. Electronic address: jgr285@ual.es.
authors.forename: J J
authors.initials: JJ
authors.lastname: Gallardo-Rodríguez
authors.affiliation: Chemical Engineering Area, University of Almería, 04120 Almería, Spain.
authors.forename: L
authors.initials: L
authors.lastname: López-Rosales
authors.affiliation: Chemical Engineering Area, University of Almería, 04120 Almería, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Sánchez-Mirón
authors.affiliation: Chemical Engineering Area, University of Almería, 04120 Almería, Spain.
authors.forename: F
authors.initials: F
authors.lastname: García-Camacho
authors.affiliation: Chemical Engineering Area, University of Almería, 04120 Almería, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Molina-Grima
authors.affiliation: Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, OH 43210, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Chalmers
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D003198:Computer Simulation; D004141:Dinoflagellida / Q000254:growth & development / Q000502:physiology*; D057446:Hydrodynamics; D058086:Microalgae / Q000502:physiology*; D033081:Shear Strength; D013816:Thermodynamics; D014783:Viscosity
keywords: Dinoflagellate; Flow contraction device; Membrane fluidity; Microalgae; Shear-sensitivity