南海北部表层海水中溶解氨基酸的分布与组成研究

Distribution and composition of dissolved amino acids in surface water of northern South China Sea

测定了2009年冬季南海北部表层海水中总水解氨基酸(THAA)、溶解游离氨基酸(DFAA)、溶解结合态氨基酸(DCAA)及叶绿素a、溶解有机碳(DOC)的浓度。调查海区THAA浓度的分布总体呈现近岸高、远岸低的特点,并且在陆坡处出现高值;DFAA浓度分布规律性则较差,但是在陆坡处也出现高值;DCAA周转速度较慢,是THAA浓度变化的主要控制因素(R=0.9935,n=48,P<0.0001)。冬季南海北部表层海水THAA主要由甘氨酸、丝氨酸、谷氨酸、丙氨酸和天门冬氨酸构成,它们占THAA的67.03%,DFAA、DCAA中的主要成分与THAA基本相同。个体氨基酸间的相关性矩阵分析显示THAA中有5对个体氨基酸间存在显著性正相关,DFAA、DCAA中分别有9对及6对个体氨基酸之间存在显著性正相关。溶解氨基酸与环境因子如叶绿素a和DOC之间均没有相关性。

The Concentrations of total hydrolyzed amino acids（THAA）,dissolved free amino acids（DFAA）,dissolved combined amino acids（DCAA）,chlorophyll a and dissolved organic carbon（DOC） in surface water of the northern South China Sea were determined in winter of 2009.The concentrations of THAA were higher in the coastal waters and lower in the open sea,though there were also some high values in the slope area.The distribution of DFAA did not exhibit regular pattern,but the concentrations of DFAA were usually high in the slope area.The major constituents of THAA in the study area were glycine,serine,glutamic acid,alanine and aspartic acid,accounting for 67.03% of THAA.Basically,DFAA and DCAA have the same major constituents as THAA.The correlation matrix of individual amino acids at all stations in the surface water showed that there were five pairs of individual amino acids have the significant positive correlation between each other in THAA,nine pairs in DFAA and six pairs in DCAA.The correlation was not found between the dissolved amino acids and environmental factors such as chlorophyll a and DOC.