Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China.
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China.
Sci Total Environ. 2019 Nov 25;693:133650. doi: 10.1016/j.scitotenv.2019.133650. Epub 2019 Jul 29.
Advanced sewage treatment by microalgae is regarded as a promising method for addressing eutrophication. To improve sewage treatment, three kinds of plant hormones including auxin (indole-3-acetic acid, IAA), cytokinin (Zeatin), and brassinosteroid, were chosen to measure the influence of plant hormones on nitrogen and phosphorus removal by Tetraselmis cordiformis and to analyze their mechanisms, including photosynthesis, nutrient metabolism, and gene transcription. The results indicated that the maximal removal efficiencies of total nitrogen and phosphate by T. cordiformis were elevated by the plant hormones by 184.3% and 53.2%, respectively. The chlorophyll a content was increased by 1.1 times by the plant hormones in comparison with the control. Moreover, after being stimulated by plant hormones, the activities of nitrate reductase (NR) and glutamine synthetase (GS) increased by 90.4% and 82.1%, respectively, in comparison with the control. Supplementation with plant hormones also significantly elevated the mRNA expression level of GS-related gene by 30.9%. This study demonstrated that plant hormones could significantly promote the nutrient removal of microalgae for sewage treatment in artificial laboratory conditions and provided theoretical support for its further practical full-scale application under variable conditions.
通过微藻进行高级污水治理被认为是解决富营养化的一种有前途的方法。为了改善污水治理，选择了三种植物激素，包括生长素（吲哚-3-乙酸，IAA）、细胞分裂素（玉米素）和油菜素内酯，以测量植物激素对菱形藻去除氮和磷的影响，并分析其机制，包括光合作用、营养代谢和基因转录。结果表明，植物激素使菱形藻对总氮和磷酸盐的最大去除效率分别提高了 184.3%和 53.2%。与对照组相比，叶绿素 a 的含量增加了 1.1 倍。此外，在植物激素的刺激下，硝酸还原酶（NR）和谷氨酰胺合成酶（GS）的活性分别比对照组提高了 90.4%和 82.1%。植物激素的补充还显著提高了 GS 相关基因的 mRNA 表达水平 30.9%。本研究表明，植物激素可以显著促进微藻在人工实验室条件下的污水治理中的营养去除，为其在不同条件下的实际全面应用提供了理论支持。
