Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam 603 102, India.
Chemosphere. 2012 Nov;89(9):1042-7. doi: 10.1016/j.chemosphere.2012.05.067. Epub 2012 Jun 15.
Power plants employ chlorination for controlling biofouling in the cooling water system. Phytoplankton drawn into the cooling water system could be impacted by chemical stress induced by the oxidizing biocide. It is likely that microalgae, being sensitive to chlorine, could suffer damage to their cellular structure and function. In this study, we present data on the effect of in-use concentrations of chlorine on the unicellular microalga, Chlorella salina. Chlorophyll autofluorescence was measured in terms of mean fluorescence intensity per cell for rapid assessment of toxicity. Viability of the cells exposed to chlorine was determined by fluorescein diacetate staining. Functionality of the photosynthetic machinery was assessed by gross primary productivity. Results from the study, which combined confocal laser scanning microscopy with image analysis, showed a significant dose-dependant reduction in chlorophyll autofluorescence, esterase activity and gross primary productivity in chlorine-treated cells. Interestingly, the cells injured by chlorination could not recover in terms of autofluorescence, esterase activity or productivity even after 18 h incubation in healthy media. Among the test points evaluated, esterase activity appeared to be sensitive for determining the chlorination-induced impact. Our results demonstrate that low-dose chlorination causes significant decrease in chlorophyll autofluorescence, intracellular esterase activity and primary productivity in Chlorella cells.
发电厂采用氯化法来控制冷却水系统中的生物污垢。被吸入冷却水中的浮游植物可能会受到氧化杀生剂引起的化学胁迫的影响。微藻很可能对氯敏感，其细胞结构和功能可能会受到损害。在这项研究中，我们提供了关于在使用浓度的氯对单细胞微藻盐藻的影响的数据。用细胞平均荧光强度来衡量叶绿素自发荧光，以快速评估毒性。用荧光素二乙酸酯染色来测定暴露于氯的细胞的活力。通过总初级生产力来评估光合作用机构的功能。这项研究结合了共聚焦激光扫描显微镜和图像分析，结果表明，在经过氯处理的细胞中，叶绿素自发荧光、酯酶活性和总初级生产力显著地依赖于剂量减少。有趣的是，即使在健康介质中孵育 18 小时后，受氯化作用损伤的细胞在自发荧光、酯酶活性或生产力方面都无法恢复。在所评估的测试点中，酯酶活性似乎对确定氯化引起的影响很敏感。我们的研究结果表明，低剂量的氯化会导致叶绿素自发荧光、细胞内酯酶活性和小球藻细胞的初级生产力显著下降。
