Impact of osmolytes on buoyancy of marine phytoplankton
Impact of osmolytes on buoyancy of marine phytoplankton
复制标题
DOI：
10.1007/s00227-002-0872-z
复制
发表时间：
2002-10-01
期刊：
影响因子：
2.4
通讯作者：
Gradmann, D
中科院分区：
文献类型：
--
作者：
Boyd, CM;Gradmann, D
海洋植物浮游细胞只有在其相对较重的结构材料（蛋白质、碳水化合物、硅酸盐）的密度过大时，才能通过掺入密度小于海水的材料来补偿，从而实现中性浮力。我们已经计算了几种海藻的密度和渗透浓度，根据已公布的值的结构材料和无机离子和其他渗透剂的浓度。的计算，将部分摩尔体积，分子质量，浓度和渗透系数，表明大多数出版的海藻细胞内渗透剂的列表是不足以提供已知存在的膨压。同样，根据已知或估计的细胞成分浓度计算的植物浮游细胞密度通常超过海水密度，这将导致整个海洋的负浮力（下沉）。我们使用渗透浓度和细胞密度的模型，其中我们补充了已知浓度的渗透剂与代理渗透剂。特别是，浓度约为100摩尔m（-3）的季铵衍生物可以解释赤字的渗透浓度和浮力。
Marine phytoplanktonic cells can achieve neutral buoyancy only if the excess density of their relatively heavy structural materials (proteins, carbohydrates, silicate) is compensated for by the incorporation of materials that have densities less than seawater. We have calculated densities and osmotic concentrations for several marine algae, based on published values of structural materials and concentrations of inorganic ions and other osmolytes. The calculations, incorporating the partial molal volume, molecular mass, concentrations and osmotic coefficients, indicate that most published listings of intracellular osmolytes in marine algae are insufficient to provide the turgor known to exist. Similarly, the density of phytoplanktonic cells, calculated on the basis of known or estimated concentrations of cellular components, generally exceeds the density of seawater, which would cause negative buoyancy (sinking) throughout. We use models of osmotic concentration and cellular density in which we supplement known concentrations of osmolytes with proxy osmolytes. In particular, concentrations of some 100 mol m(-3) of quaternary ammonium derivatives can explain the deficits of both osmotic concentration and buoyancy.