National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Cochin-16, Kerala, India; School of Environmental Studies, Cochin University of Science and Technology, Cochin-22, Kerala, India.
National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Cochin-16, Kerala, India.
Aquat Toxicol. 2019 Dec;217:105317. doi: 10.1016/j.aquatox.2019.105317. Epub 2019 Sep 26.
The microalga Chlorella vulgaris is one of the prominent and most widely distributed green microalgae found in aquatic environments, often used in toxicity tests due to its sensitivity to various pollutants. To examine the toxicity of metals found in the effluent discharges from an electroplating industry, physicochemical parameters in the microalga C. vulgaris were measured. pH, turbidity, total dissolved solids, color, and the concentrations of metals such as chromium (1.97 mg/L), mercury (104.2 mg/L), and zinc (167.25 mg/L) were found exceeding the permissible limits. Several endpoints such as total protein content, reactive oxygen species (ROS) production, photosynthetic pigment contents, and antioxidant enzymatic activities, including those of superoxide dismutase (SOD) and catalase (CAT), were measured in C. vulgaris in response to treated electroplating industrial effluent (TEPIE). In addition, concentration-dependent morphological changes were also observed in response to TEPIE. Under both acute and chronic TEPIE exposure, increase in the ROS level was observed indicating increased production of ROS in C. vulgaris cells. The total protein and chlorophyll contents were found to be gradually decreasing in an effluent concentration-dependent manner. Moreover, lower concentrations of effluent stimulated the antioxidant enzyme systems. A concentration-dependent increase was observed in both SOD and CAT enzymatic activities. The results indicated toxic impairments by the effluent on the function of C. vulgaris in response to both acute and chronic exposure, indicating an urgent need of proper treatment processes/modification of the existing one of TEPIE, with continuous monitoring of the discharge of the pollutants into the aquatic ecosystems using biological assays.
微藻小球藻是一种在水生环境中分布广泛的优势绿藻，由于其对各种污染物的敏感性，常被用于毒性测试。为了研究电镀工业废水中金属的毒性，测量了微藻小球藻中的理化参数。发现 pH 值、浊度、总溶解固体、颜色以及铬（1.97mg/L）、汞（104.2mg/L）和锌（167.25mg/L）等金属的浓度均超过了允许限值。在电镀工业废水（TEPIE）处理后，测量了小球藻中的几个终点，如总蛋白含量、活性氧（ROS）产生、光合色素含量和抗氧化酶活性，包括超氧化物歧化酶（SOD）和过氧化氢酶（CAT）。此外，还观察到了对 TEPIE 的浓度依赖性形态变化。在急性和慢性 TEPIE 暴露下，ROS 水平均升高，表明小球藻细胞中 ROS 的产生增加。总蛋白和叶绿素含量逐渐降低，呈废水浓度依赖性。此外，较低浓度的废水刺激了抗氧化酶系统。SOD 和 CAT 酶活性均呈浓度依赖性增加。结果表明，废水对小球藻功能造成了毒性损伤，无论是急性暴露还是慢性暴露，都需要对 TEPIE 进行适当的处理工艺/修改，并通过生物测定对污染物排放到水生生态系统进行持续监测。
