Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
Bioresour Technol. 2023 Mar;372:128700. doi: 10.1016/j.biortech.2023.128700. Epub 2023 Feb 2.
The nitrogen removal performance and biological mechanism of Platymonas helgolandica var. Tsingtaoensis (P. helgolandica) were investigated in treating mariculture wastewater under different light: dark (L:D) photoperiods. The growth of P. helgolandica was positively correlated with the photoperiods from 6L:18D to 15L:9D, and the highest photosynthetic activity appeared under 6L:18D photoperiod on day 3. P. helgolandica exhibited the highest removal efficiencies of total nitrogen and COD at 89 % and 93 % under 15L:9D photoperiod, respectively. NH-N assimilation was proportional to the photoperiods from 6L:18D to 15L:9D and longer illumination promoted NO-N removal. However, the highest NO-N reduction rate was achieved under 12L:12D photoperiod. The different nitrogen-transformed enzymatic activities were affected by photoperiod. Transcriptome revealed that unigenes were enriched in nitrogen metabolism and photosynthesis pathways, of which the functional gene expression was up-regulated significantly. This study provides insights into the optimization of photoperiod for mariculture wastewater treatment by P. helgolandica.
黑暗（L:D）光周期下，青岛等鞭金藻（P. helgolandica）处理海水养殖废水中的脱氮性能和生物机制。P. helgolandica 的生长与光周期呈正相关，从 6L:18D 到 15L:9D，第 3 天的最高光合作用出现在 6L:18D 光周期下。在 15L:9D 光周期下，P. helgolandica 对总氮和 COD 的去除率最高，分别为 89%和 93%。NH-N 的同化与光周期呈正相关，从 6L:18D 到 15L:9D，光照时间延长促进了 NO-N 的去除。然而，NO-N 的还原率在 12L:12D 光周期下达到最高。不同的氮转化酶活性受光周期的影响。转录组分析表明，基因主要富集在氮代谢和光合作用途径中，其中功能基因表达显著上调。本研究为等鞭金藻处理海水养殖废水的光周期优化提供了依据。
