Causes of Shear Sensitivity of the Toxic Dinoflagellate Protoceratium reticulatum
Causes of Shear Sensitivity of the Toxic Dinoflagellate Protoceratium reticulatum
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DOI：
10.1002/btpr.161
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发表时间：
2009-05-01
影响因子：
2.9
通讯作者：
Molina Grima, E.
中科院分区：
文献类型：
--
作者：
Gallardo Rodriguez, J. J.;Sanchez Miron, A.;Molina Grima, E.
甲藻已被证明非常难以培养，因为它们受到低水平剪切力的抑制。与静态对照培养物相比，通过间歇暴露于整体平均剪切速率低至0.3 s（-1）的湍流水动力环境，有毒甲藻Protoceratium，reticulatum的比生长速率大大降低。水动力似乎诱导细胞内活性氧（ROS）的产生，这导致细胞脂质过氧化，并最终导致细胞损伤。暴露于损伤水平的剪切速率与细胞中的脂质过氧化物水平升高相关，但通过流式细胞术直接测量的ROS水平与剪切诱导的细胞损伤无关。这显然是因为所测量的ROS水平不能区分通常由光合作用产生的ROS和由于流体动力学剪切力而产生的额外ROS。将细胞连续置于约0.3 s（-1）的整体平均剪切速率下24 h，导致叶绿素a、多甲藻素和甲藻黄素水平升高，因为细胞显然试图通过产生潜在的抗氧化剂色素来对抗剪切场的破坏作用。在静态培养中，二氧化碳的限制产生了一个小的，但可测量的增加活性氧。向培养基中添加抗坏血酸（0.1 mM）导致对脂质过氧化的显著保护作用，允许细胞在破坏性剪切速率水平下生长。这证实了使用抗氧化剂添加剂作为一种有效的策略，以对抗剪切敏感的甲藻培养的光生物反应器中的湍流的破坏性影响。(C)2009年美国化学工程师学会生物技术。程序：25：792-800，2009
Dinoflagellates have proven extremely difficult to culture because they are inhibited by low-level shear forces. Specific growth rate of the toxic dinoflagellate Protoceratium, reticulatum was greatly decreased compared with static control culture by intermittent exposure to a turbulent hydrodynamic environment with a bulk average shear rate that was as low as 0.3 s(-1). Hydrodynamic forces appeared to induce the production of reactive oxygen species (ROS) within the cells and this caused peroxidation of cellular lipids and ultimately cell damage. Exposure to damaging levels of shear rate correlated with the elevated level of lipoperoxides in the cells, but ROS levels measured directly by flow cytometry did not correlate with shear induced cell damage. This was apparently because the measured level of ROS could not distinguish between the ROS that are normally generated by photosynthesis and the additional ROS produced as a consequence of hydrodynamic shearforces. Continuously subjecting the cells to a bulk average shear rate value of about 0.3 s(-1) for 24-h caused an elevation in the levels of chlorophyll a, peridinin and dinoxanthin, as the cells apparently attempted to counter the damaging effects of shear fields by producing pigments that are potential antioxidants. In static culture, limitation of carbon dioxide produced a small but measureable increase in ROS. The addition of ascorbic acid (0.1 mM) to the culture medium resulted in a significant protective effect on lipid peroxidation, allowing cells to grow under damaging levels of shear rates. This confirmed the use of antioxidant additives as an efficient strategy to counter the damaging effects of turbulence in photobioreactors where shear sensitive dinoflagellates are cultivated. (C) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 25: 792-800, 2009