Abstract

A comparison of the response of freshwater alga Chlorella vulgaris Beijer. on a quantitatively identical change in tonicity of growth medium by different osmotics (NaCl and sucrose) has been studied. Upon an increase in growth-medium osmotic potential (regardless the nature of osmoticum), increased thermogenesis and decreased oxygen absorption by Chlorella is observed first. The difference in the reaction of Chlorella to equiosmotic concentrations of NaCl and sucrose is revealed. Upon an increased salt background, thermogenesis and photosynthetic activity decreases in comparison with the control and the respiration rate is close to the control. In the presence of sucrose, the culture has a higher level of thermogenesis, respiration, and photosynthesis. Sodium chloride does not cause significant changes in ultrastructure of Chlorella and does not lead to significant changes in the diffusional decay of water magnetization in comparison with the control. Under sucrose stress, a change in the cell shape indicating cytorhysis is revealed. The effective water-diffusion coefficient (according to NMR data) decreases, which also indicates the reduction of cell sizes. Sucrose affects Chlorella as a nonpenetrating osmotically active substance. Under moderate hyperosmotic stress, the toxicity of NaCl is a smaller problem for freshwater microalga Chlorella than the partial dehydration caused by sucrose.

中文翻译：

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中度高渗胁迫对寻常小球藻超微结构和能量代谢指标的影响

摘要

淡水藻类小球藻Beijer反应的比较。研究了不同渗透压（NaCl和蔗糖）对生长培养基的张力变化的定量相同影响。随着中等增长的渗透势（无论渗透膜的性质如何）增加，绿藻的产热增加和氧气吸收减少首先被观察。揭示了小球藻与NaCl和蔗糖等渗浓度反应的差异。当盐的背景增加时，与对照相比，产热和光合作用活性降低，并且呼吸速率接近于对照。在蔗糖的存在下，培养物具有更高水平的生热，呼吸和光合作用。与对照相比，氯化钠不会引起小球藻的超微结构发生显着变化，也不会导致水磁化强度的扩散衰减发生显着变化。在蔗糖胁迫下，揭示了细胞形状的变化，表明细胞溶解。有效水扩散系数（根据NMR数据）降低，这也表明细胞尺寸减小。蔗糖影响小球藻为非渗透性渗透活性物质。在中等高渗胁迫下，与蔗糖引起的部分脱水相比，氯化钠对于淡水微藻小球藻的毒性较小。。