氨基酸降解指数（Dauwe DI指数）在溶解有机氮中的验证和再修订

发布时间：2018-03-03 16:46

本文选题：溶解态氨基酸　切入点：南海　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：溶解有机物的研究是生物地球化学的重要研究内容,溶解有机物的成分和分布的研究对于研究海洋碳循环十分重要。溶解态氨基酸是溶解有机物的重要成分之一,也是溶解有机氮的重要的储库。溶解态氨基酸作为水体中重要的生源物质,其来源和去除过程与浮游植物和分解者的活动紧密相关。水体中溶解态氨基酸的研究对于认识溶解有机碳和有机氮的来源、转化和循环具有重要的意义。有机物降解过程中,氨基酸的摩尔百分比会以特定的方式变化,并由此发展了 DauweDI(Degradation Index)指数指征颗粒有机物和沉积物中有机质的降解状态。虽然Dauwe DI指数是指征颗粒态和沉积物中有机质成岩状态的强有力的参数,但是该指数在溶解有机物中的应用有待验证和修订。本研究基于前人工作的基础上,结合本实验室的条件,利用高效液相色谱技术(外标法)对南海陆坡区、西太平洋、长江、海南文昌河和北极海湾河的溶解态氨基酸进行了分析,并在研究溶解态氨基酸分布的基础上,对溶解态的Dauwe DI指数进行验证和再修订。氨基酸成分和分布对于认识Dauwe DI指数对于有机质降解状态的指征有重要的意义。南海的研究的结果表明:在时间连续站垂直方向上,溶解态氨基酸的浓度随着深度有减小的趋势,在400m处,出现溶解态氨基酸的极大值,表征了特征来源的有机质的输入,很可能反映了中层水生物的贡献,而DauweDI指数却没有得到相同的结果;从氨基酸的成分来看,溶解态氨基酸的主要是由中性氨基酸和酸性氨基酸构成的,其中以中性氨基酸为主,且占优势的氨基酸组成基本相同,甘氨酸丰度最高,其次为天冬氨酸、丙氨酸、谷氨酸、丝氨酸等氨基酸,氨基酸成分的相似性暗示了 DI指数统一定量化表达有机质降解程度的可能性;甘氨酸的百分含量指征了南海溶解有机质随着深度增加降解程度增加,而Dauwe DI指数与甘氨酸的百分含量的相关关系,以及其大小的范围说明该指数的系数需要进行再修订。河流的研究结果表明,由于其地理环境、水文条件等方面的明显差异,氨基酸有明显的时空变化,其中长江甘氨酸所占的摩尔百分比显著高于其它河流,D型精氨酸的含量也显著高于其它河流。河流中颗粒态和溶解态氨基酸成分存在差异,甘氨酸、丙氨酸在溶解态中的含量相对更高,亮氨酸、苯丙氨酸、缬氨酸等氨基酸在颗粒态有机质中的含量相对更高,D型氨基酸在溶解态中所占的比例更高,溶解态氨基酸和颗粒态氨基酸成分的差异表明了直接引用Dauwe DI指数到溶解态中会存在风险。Dauwe DI指数在不同河流中的值都超出了之前对于该指数的定义,这说明了在河流溶解有机物中该指数需要进行再修订。此外,在长江,DauweDI指数与其他降解参数呈现良好的相关关系,在北极和海南,这种相关关系较弱或不存在,这是由于在溶解和颗粒有机质成岩过程中,甘氨酸都表现的相对富集,同时在长江中甘氨酸的含量很高,甘氨酸对于Dauwe DI指数的影响可能掩盖了其他氨基酸的统计信号。在研究中发现,Dauwe DI指数在指征溶解态氨基酸的降解时存在一定的问题,这表现在:在河流和海洋水体中,根据DauweDI指数计算的DI指数都超出了原来对该指数范围的定义;在某些区域,例如海南和南海,该指数与氨基酸对映体的比例等参数的相关性与已有的认知不相符;溶解态氨基酸成分和颗粒态氨基酸存在较大的差异,甘氨酸等氨基酸在溶解态有机质中的百分含量相对更高,而亮氨酸等氨基酸在颗粒态有机质中的百分含量更高,成分的差异导致了 Dauwe DI指数在溶解态的应用中存在问题。基于这样的问题,本研究对DauweDI指数进行再修订。在引用文献中海洋环境的溶解态氨基酸数据的基础上,本研究补充了西太平洋和南海陆坡的溶解态氨基酸数据,对Dauwe DI指数的因子系数进行重新计算。从主成分分析(PCA)的数据库来看,本研究中PCA分析的数据库包含了更广阔的范围,从"新鲜的"的溶解有机物到西太平洋深水处的高降解程度的溶解有机物。本文对修正后的DI指数在河流和海洋有机物中进行了验证,结果表明:修正后的DI指数在本研究中能更为有效地指征溶解有机物的降解程度。
[Abstract]:Study on dissolved organic matter is an important research content of biogeochemistry, study the composition and distribution of dissolved organic matter is very important for the research on the marine carbon cycle. The dissolved amino acid is one of the important components of dissolved organic matter, important reservoir is dissolved organic nitrogen. The dissolved amino acids as an important source material in water that is closely related to the origin and removal process with phytoplankton and decomposer activity. Study of dissolved amino acids in water for recognizing sources of dissolved organic carbon and organic nitrogen, plays an important role in transformation and circulation. Organic matter degradation process, the molar ratio of amino acids in a specific way, and thus the development of DauweDI (Degradation Index) refers to the degradation of organic matter index sign of particulate organic matter and sediments. Although the Dauwe DI index refers to organic particulate and sediment syndrome Quality parameters of strong rock state, but the application of the index in the dissolved organic matter in the yet to be verified and revised. This research is based on the basis of previous work, combined with the present conditions in our laboratory, using high performance liquid chromatography (external standard method) on the slope of the South China sea, Western Pacific Ocean, the Yangtze River, dissolved amino acid Hainan Changhe and Arctic Bay River are analyzed, and based on the study of dissolved amino acids on the distribution of dissolved Dauwe, DI index is verified and revised. Then amino acid composition and distribution for understanding the Dauwe DI index for degradation of organic matter indications has important significance. The research results show that the South China Sea station: continuous vertical direction in time, concentration of dissolved amino acids with depth decreased at 400m, the maximum value of dissolved amino acids, characterized the characteristics of the organic matter from the input, it is May reflect the middle water biological contribution, while the DauweDI index did not get the same results; from the amino acid composition, dissolved amino acids are mainly composed of neutral and acidic amino acids, the neutral amino acids, amino acid and the dominant composition is basically the same, the highest abundance of glycine, followed by aspartic acid, alanine, glutamic acid, serine and other amino acids, amino acid similarity implies that DI index system must quantify the possibility of degradation degree of organic matter; content of glycine indications of the South China Sea dissolved organic matter degradation degree increased with the increase of the depth, and the correlation between the percentage of Dauwe DI index and glycine, and the size of the index coefficient needs to be revised. River research results show that, due to its geographical environment, hydrology conditions and other aspects of the Ming Dynasty Significant difference, amino acids have obvious spatiotemporal variation, the molar percentage of glycine for Yangtze River was significantly higher than that of other rivers, the content of D arginine is significantly higher than that of other rivers. The rivers in particulate and dissolved amino acids differences in dissolved content of glycine, alanine in higher, leucine, phenylalanine the content of amino acid, valine in particulate organic matter is relatively higher, higher type D amino acids in dissolved in proportion, the difference of dissolved amino acids and particulate amino acid composition shows a direct quote Dauwe DI index to the dissolved state can exist in different rivers.Dauwe DI index value of risk beyond the definition of the index before, it shows that in the dissolved organic matter in the index needs to be revised. In addition, in the Yangtze River, DauweDI index and other parameters show good degradation Good relationship, in the Arctic and Hainan, this relationship is weak or nonexistent, which is due to the dissolved and particulate organic matter in the diagenetic process, the relative enrichment of glycine were at the same time, content of glycine in the Yangtze River is very high, the Dauwe DI index for glycine influence may mask the statistical signal of other amino acids the study found that the Dauwe DI index, there are some problems in the degradation of dissolved amino acid syndrome, which is reflected in: in the river and sea water, according to the calculation of DauweDI index DI index exceeded the original of the definition refers to the number range; in some regions, such as Hainan and the South China Sea, correlation with the existing index and the proportion of amino acid enantiomers on the parameters of the cognition is not consistent; there is a great difference between dissolved and particulate amino acid composition of amino acid, glycine and other amino acids in the dissolved organic matter in The percent content is relatively higher and higher leucine amino acid content in the particulate organic matter in the composition due to the difference of Dauwe DI index exists in the application of dissolved the problem. Based on this, the research on the DauweDI index was revised. Based on the reference data of dissolved amino acids in marine environment in the literature, this study adds to the Western Pacific and the South China Sea continental slope of dissolved amino acid data, factor coefficient of Dauwe DI index were recalculated. The principal component analysis (PCA) database, PCA database on this research included a wider range of dissolved organic matter from dissolved organic the fresh "to the high degree of degradation of the Western Pacific deep water. In this paper, the modified DI index in river and marine organisms are verified, the results show that the modified DI index in this study It is more effective to indicate the degree of degradation of dissolved organic matter.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P734

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