| 摘要: |
| 生物可利用性有机氮(BDON)在海洋生态系统氮循环中起着关键作用, 氨基酸是BDON的重要组成部分, 也是DON生物可利用性的重要指示物。本研究阐述2021年春、夏季南黄海水体中总溶解氨基酸(THAA)组成和时空分布特征, 并对南黄海DON生物可利用性进行分析。南黄海DON物质的量的浓度(下文简称浓度)分布呈现近岸高、远岸低的特征, 夏季THAA水平分布上呈现北高南低的特征。夏季南黄海THAA的平均浓度(1.11±0.34μmol/L)略高于春季(0.98±0.28 μmol/L) 而DON平均浓度春季(8.17±5.06 μmol/L)明显高于夏季(5.72±2.82 μmol/L)。南黄海氨基酸主要由丝氨酸、甘氨酸+苏氨酸、谷氨酸、精氨酸、丙氨酸等构成, 其占总氨基酸的比例春季(61.51%)略低于夏季(65.69%)。南黄海以硅藻为主的浮游植物群落是水体氨基酸的重要来源, 浒苔绿潮暴发显著影响了水体氨基酸的组成。夏初浒苔绿潮进入消亡和降解阶段, 这可能是南黄海35°N以北海域DON具有很高的生物可利用性的重要原因。 |
| 关键词: 总溶解态氨基酸 溶解有机氮 南黄海 降解因子 生物可利用性 |
| DOI：10.11759/hykx20230526002 |
| 分类号:X55 |
| 基金项目:国家自然科学基金-山东省联合基金(1906210) |
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| Composition characteristics of dissolved amino acids and bioa-vailability of dissolved organic nitrogen in the South Yellow Sea |
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SUN Hu, GAO Xinpeng, MENG Xiao, SU Rongguo
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Key Laboratory of Marine Chemistry Theory and Engineering Technology, Ministry of Education, School of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China
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| Abstract: |
| Bioavailable dissolved organic nitrogen (BDON) plays a vital role in the nitrogen cycle of marine ecosystems. Amino acids are an important component of BDON, which can serve as an indicator of dissolved organic nitrogen (DON) bioavailability. This study investigated the spatial distribution of hydrolysable amino acid (THAA) and bioavailability of DON in the South Yellow Sea in the spring and summer of 2021. The distributions of THAA and DON exhibited high concentrations near shore and low concentrations in offshore. The average concentrations of THAA were 0.98±0.28 and 1.11±0.34 μmol/L in the spring and summer, respectively. The average concentrations of DON were 8.17±5.06 and 5.72±2.82 μmol/L in the spring and summer, respectively. Amino acids in the South Yellow Sea mainly included serine, glycine + threonine, glutamic acid, arginine, and alanine, which accounted for 61.51% of the total amino acids in spring and 65.69% of the total amino acids in summer. The phytoplankton community dominated by diatoms is an important source of amino acids in the South Yellow Sea. The outbreak of green tide caused by Ulva prolifera in summer significantly changed the composition of amino acids in the seawater. In early summer, DON in the South Yellow Sea showed high bioavailability in the area north of 35° N that supported the green tide in the late period. |
| Key words: total hydrolyzed amino acids dissolved organic nitrogen the South Yellow Sea degradation index bioavailability |
