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中国近海表层沉积物中氨基酸组成特征及生物地球化学意义
Amino acid composition and its biogeochemistry implications of surface sediments in China coastal area
投稿时间:2009-05-13  修订日期:2009-08-17
DOI:
中文关键词:  表层沉积物  有机质  氨基酸  降解程度  再生潜力
英文关键词:surface sediment  organic matter  amino acid  degree of degradation  potential regeneration
基金项目:国际海底区域研究开发“十一五”项目“深海生物地球化学过程在地质体中的记录
作者单位邮编
王丽玲 中国科学院广州地球化学研究所 510640
胡建芳* 中国科学院广州地球化学研究所 510640
唐建辉 中国科学院烟台海岸带可持续发展研究所 
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中文摘要:
        通过对中国近海表层沉积物的总水解氨基酸(THAA)分析,结合总有机碳(TOC)、总氮(TN)及有机质的13C、15N分析,探讨了沉积物中有机质含量、来源、降解程度等一系列生物地球化学意义。结果表明:样品中THAA含量为440~2370 μg/g(干重),TOC、TN和OC/N比值分别为0.16%~1.08% (wt)、0.05% ~0.2% (wt)和3.3 ~7.7,13Corg 及15N分别为-25.0‰~-21.2‰、3.9‰ ~5.7‰。沉积物颗粒大小对有机质的含量有重要影响,THAA与TOC、TN也有着相似的空间分布特征。沉积物中有机质来源以海洋浮游生物输入为主,陆源输入亦有少量的贡献,酸性与中性氨基酸的比值指示了采样区域沉积环境偏碱性。氨基酸态氮对总氮贡献率(TAAN)在黄海海域受到秋季黄海冷水团活动的影响,表层沉积物氨基酸态氮的再生潜力要高于南海海域,而浙闽沿岸海域由于无机氮的大量输入,沉积物中氨基酸态氮得到了稀释。利用Asp/β-Ala、Glu/γ-Aba和(Phe+Tyr)/(β-Ala+γ-Aba)三个指标,结合主成分分析方法,推断出沉积物中有机质降解程度为:黄海海域,大连和山东半岛附近采集的样品有机质较新鲜,其余样品降解程度较高;长江口及浙闽沿岸样品有机质较新鲜;南海海域样品有机质降解程度较高。随着有机质降解程度的增加,氨基酸态碳对总有机碳的贡献率(TAAC)相应减少。个体氨基酸化学性质对其在沉积物中保存程度的影响有限,氨基酸在沉积物中的组成分布是各因素共同作用的结果。
英文摘要:
       The total hydrolysable amino acid (THAA), total organic carbon (TOC), total nitrogen (TN) and the isotopic compositions (13Corg and 15N) of organic matter (OM) were determined in surface sediments of coastal areas of China. The contents of THAA in the sediments are in the range between 440 and 2370 μg/g (dry weight). The TOC, TN, C/N ratios, 13Corg and 15N are in the range of 0.16%~1.08% (wt), 0.05% ~0.20% (wt), 3.3 ~7.7, -25.0‰~-21.2‰ and 3.9‰ ~5.7‰, respectively. The 13Corg values indicate that OM derived from two sources, terrestrial and marine. Ratios of acidic amino acids to neutral amino acids show that the sedimentary environment was slightly alkaline. The spatial distributions of THAA, TOC and TN are broadly similar, suggesting that the OM is closely related to the particle size of the sediments. Factors such as hydrodynamic condition, variation of biomass, degradation of OM and the influx of dissolved inorganic nitrogen from land are responsible for the contributions of amino acid to total nitrogen (TAAN). The potential regeneration of nitrogen from amino acids in the sediments taken from the Yellow Sea is stronger than that from the South China Sea due to the influence of the cold water mass in the Yellow Sea. The contents of TAAN in the sediments taken from Zhejiang to Fujian coastal-line are low, which might be caused by the dilution of large input of inorganic nitrogen. The ratios of Asp/β-Ala, Glu/γ-Aba,(Phe+Tyr)/(β-Ala+γ-Aba)and the principal component analysis (PCA) indicate that the degrees of degradation of sedimentary OM are different from each other in the studied area. With the increasing of OM degradability, contribution of amino acid to TOC (TAAC) reduced correspondingly. The distributions of individual amino acid indicate that the compositions of amino acids in the surface sediments are related to several factors.
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