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Shear-induced changes in membrane fluidity during culture of a fragile dinoflagellate microalga

J J Gallardo-Rodríguez1, F García-Camacho, A Sánchez-Mirón

  • 1Dept. of Chemical Engineering, University of Almería, 04120 Almería, Spain. jgr285@ual.es

Biotechnology Progress
|October 29, 2011
PubMed

Insights

Pluronic F68 (PF68) protects marine microalgae Protoceratium reticulatum from shear stress by increasing membrane fluidity, not decreasing it. This challenges previous assumptions about PF68

Area of Science:

  • Marine biology
  • Biochemistry
  • Cellular physiology

Background:

  • Pluronic F68 (PF68) is a common shear-protective agent.
  • Its protective mechanism in animal cells is often attributed to reduced membrane fluidity.
  • The effect of PF68 on microalgal cell membranes under shear stress is less understood.

Purpose of the Study:

  • To investigate the shear-protective effect of PF68 on the marine dinoflagellate microalga Protoceratium reticulatum.
  • To determine the impact of PF68 on P. reticulatum cell membrane fluidity under varying turbulence levels.
  • To elucidate the mechanism behind PF68's shear protection in microalgae.

Main Methods:

  • Culturing Protoceratium reticulatum under different Pluronic F68 concentrations.
  • Subjecting cultures to sublethal and lethal turbulence regimens.
  • Measuring cell membrane fluidity and lipoperoxide levels.

Main Results:

  • Pluronic F68 exhibited a shear-protective effect on P. reticulatum at concentrations up to 0.5 g L(-1).
  • PF68 supplementation increased, rather than decreased, the fluidity of P. reticulatum cell membranes.
  • Membrane fluidity was significantly influenced by lipoperoxide levels generated under lethal agitation.

Conclusions:

  • The shear-protective mechanism of PF68 in P. reticulatum differs from that observed in animal cells.
  • Increased membrane fluidity, not reduced fluidity, is associated with PF68's protective effect in this microalga.
  • Lipoperoxide accumulation under shear stress plays a critical role in regulating microalgal membrane fluidity.

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