Plant Biotechnology Laboratory, Department of Botany, Mohanlal Sukhadia University, Udaipur, Rajasthan, 313001, India.
Environ Sci Pollut Res Int. 2019 Sep;26(26):26991-27001. doi: 10.1007/s11356-019-05844-1. Epub 2019 Jul 16.
Commercial usage of ZnO nanoparticles has increased recently due to its versatile applications, raising serious environmental concern because of its ultimate release of nanoparticles in aquatic ecosystem. Therefore, it is important to understand the impact of ZnO nanoparticle toxicity especially on algal flora, which is the primary producer in the aquatic food chain. In the current study, algal growth kinetics was assessed after the exposure of zinc oxide nanoparticles and its bulk counterpart to Coelastrella terrestris (Chlorophyceae). Zinc oxide nanoparticles were found to be more toxic (y = 34.673x, R = - 0.101, 1 mg L nanoparticle (NP)) than bulk (y = 50.635x, R = 0.173, 1 mg L bulk) by entrapping the algal cell surface. Higher toxicity may be due to oxidative stress within the algal cell as confirmed through biochemical analysis. Biochemical parameters revealed stressful physiological condition in the alga under nanoparticle exposure, as lactate dehydrogenase release (18.89 ± 0.2 NP; 13.67 ± 0.2 bulk), lipid peroxidation (0.9147 ± 1.2 NP; 0.7480 ± 0.8 bulk), and catalase activity (4.77 ± 0.1 NP; 3.32 ± 0.1 bulk) were found higher at 1 mg L in the case of nano-form. Surface adsorptions of nanoparticles were observed by SEM. Cell organelle damage, cell wall breakage, and cytoplasm shrinkage were found as responses under toxic condition through SEM and TEM. Toxicity was found to be influenced by dose concentration and exposure period. This study indicates that nano-form of ZnO is found to be more toxic than bulk form to freshwater alga.
由于氧化锌纳米粒子的多种应用，其商业用途最近有所增加，由于其最终会释放到水生生态系统中的纳米粒子，因此引起了严重的环境问题。因此，了解氧化锌纳米粒子毒性的影响，特别是对藻类植物的影响非常重要，藻类植物是水生食物链中的初级生产者。在目前的研究中，评估了暴露于氧化锌纳米粒子及其块状物后藻类生长动力学对陆生集球藻（绿藻门）的影响。结果发现，纳米粒子比块状物更具毒性（y = 34.673x，R = -0.101，1 mg L 纳米粒子（NP）），因为它会困住藻类细胞表面。更高的毒性可能是由于藻类细胞内的氧化应激，这通过生化分析得到了证实。生化参数表明，在纳米粒子暴露下，藻类处于应激生理状态，因为乳酸脱氢酶释放（18.89 ± 0.2 NP；13.67 ± 0.2 块状物），脂质过氧化（0.9147 ± 1.2 NP；0.7480 ± 0.8 块状物）和过氧化氢酶活性（4.77 ± 0.1 NP；3.32 ± 0.1 块状物）在纳米形式下 1 mg L 时更高。通过 SEM 观察到纳米粒子的表面吸附。通过 SEM 和 TEM 观察到，在有毒条件下，发现细胞器官损伤、细胞壁破裂和细胞质收缩作为响应。毒性受剂量浓度和暴露时间的影响。本研究表明，纳米形式的 ZnO 比块状形式对淡水藻类更具毒性。
