湖泊沉积物中生物大分子的研究

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	湖泊沉积物中生物大分子的研究
	梁小兵
	2001
学位授予单位	中国科学院地球化学研究所
学位授予地点	中国科学院地球化学研究所
学位名称	博士
学位专业	地球化学
关键词	湖泊沉积物生物大分子蛋白质微生物测定方法阿哈湖百花湖洱海物质循环有机质硫酸盐还原菌
摘要	湖泊沉积物中生物大分子在物质循环、微生物作用和环境信息指示方面其着重要的作用。对湖泊沉积物研究中，注重对无机成分变化和环境记录的研究，也充分认识到了生物作用的重要性。本项目首次选用了生物大分子这条新的途径，对湖泊沉积物中微生物、无机物及其环境地球化学过程进行了研究。本文以云贵高原的三个典型湖泊为研究对象，通过对湖泊沉积物中生物大分子的研究，揭示了DNA、RNA和蛋白质及其水解产物核苷酸、氨基酸在不同沉积物层面上的变化规律。将湖泊沉积物中生物大分子与微生物种类及其产生的生物作用联系起来，探讨它们的生物地球化学循环过程和环境效应。通过本文的研究，得出了以下主要结论及新的认识：1．湖泊沉积物中生物大分子起着重要的作用。运用学科交叉的优势，进行系统的研究，是一条的新途径。通过对生物大分子的研究不但可以认识它们在物质循环过程中的重要作用，还能利用它们储藏的遗传信息与生物信息有对应关系，指示微生物和环境变化等方面的信息。2．蛋白质是生物体内主要的生物大分子，又是湖泊沉积物中有机质的组成成分。蛋白质的降解是有机质降解的重要组成部分。本文探讨了蛋白质变化与湖泊沉积物中物质循环过程的耦合关系，而且将蛋白质的动态变化与氨基酸和微生物联系起来进行综合研究，探讨了它们之间相互的影响。输入沉积物的生物细胞释放的蛋白质在微生物分泌的胞外酶和细胞残留的蛋白酶的作用下水解成氨基酸，后者可作为营养物质被微生物吸收利用再合成蛋白质。这种降解和合成的动态变化不仅是生物地球化学循环的组成部分，而且影响微生物的活动。3．蛋白质和氨基酸在湖泊沉积物不同层面的含量和分布的研究，揭示了蛋白质降解规律、蛋白质储藏N素的潜在环境效应、氨基酸作为微生物营养源对微生物的影响以及氨基酸态N的湖泊环境效应。4．揭示了蛋白质和DNA在湖泊沉积物中的存在状态。根据它们与无机矿物结合而使稳定性提高的特点，探讨了它们在地质环境下的保留及分离提取的新思路和新方法。5．DNA、RNA和核苷酸在湖泊沉积物中的含量、分布和变化规律的研究，揭示了遗传物质在湖泊沉积物中随时间和空间的变化规律。DNA的分子系统发生学的研究是鉴定湖泊沉积物中微生物群落的新兴而有效的方法。洱海沉积物中特征性DNA片段的体外扩增及鉴定方法的建立和运用，为进一步开展湖泊沉积物中生物的研究奠定了基础。对真细菌的研究揭示了这类微生物与生物地球化学循环的耦合关系。真细菌直接参与Fe、Mn的氧化还原过程、氮循环过程，我们初步阐述了以上循环过程的微生物作用机理，提出了用微生物作用的观点对有关化学研究结果的新的阐释。6．湖泊沉积物中微生物的分布受多种因素的影响，除氧含量、pH值、氧化还原电位和温度外，营养源是重要的影响因素，各种营养素的含量、质量和相对比例对微生物群落的消长影响很大。生物大分子的C：N比很低，是易变的有机质和优质的营养源。提出了有机质分类的新方法并阐述了该方法的优点及环境意义。7．提出了蛋白质是硫的暂宿体和潜在来源的新观点。蛋白质是有机硫向无机硫转化，无机硫向有机硫转化的枢纽。通过蛋白质的生物合成和降解完成这种转化过程。湖泊沉积物中硫循环过程是一个多途径的、各种形态硫参与的循环过程，其中微生物及其代谢过程是硫循环的生物机理。参与硫循环的微生物种类有多种类型，代谢途径和电子传递途径多种多样。8．湖泊沉积物中C、N、S、Fe、Mn等循环过程和生物大分子的变化及有机质的降解是相互联系的。微生物是这些过程中的主要因素，其类型及分布受多种因素的调节控制而发生变化。
其他摘要	Biological macromolecules in lake sediments are very important in substance cycles, microbial actions and indication of environmental information. On the research of Lake sediments, changes of inorganic components and environmental records are paid attention to, furthermore the importance of biological action was realized. A new approach of biological maeromolecules was chosen to study organisms, inorganic components and their process of emvrionmental geochemistry in the item. Three typical lakes on Yunnan-Guizhou Plateur was chosen to be research objects. The change regulation of DNA, RNA, protein and their hydrolysates-nucleotides and amino acids in different sedimental depth was elucidated by studying biological macromolecules in lake sediments. Biological macromolecules and varieties of microbes and their biological actions are linked to discuss their bio-geochemical cycles and their environmental effects. Based on the study of the items, the main conclusions we have obtained are as follows: 1. Biological macromolecules are important in lake sediments. It is a new pathway to study them with subject intersection. By studying biological macromolecules, we can not only realize their important function in substance cycles but also utilize their genetic information which corresponds to organism to indicate information of microbes and environmental change. 2. Protein is not only the main biological macromolecule in orgamsms but also the important components of organic matter. Its decomposition is the part of organic matter decomposition. We have studied the couplingrelations of change of protein and substance cycles in lake sediments, and do all-around research among protein dynamics, amino acids and microbes so as to realize their mutual influences. Cells which were input to sediments are hydrolysed to amino acids by extracellar enzymes that was excreted from microbes or remains from other cells. Amino acids are able to be absorbed by microbes to re-synthesize protein. The dynamics of decomposition and composition is not only the section cf biogeoehemical cycles, but also effects microbe activities. 3. Research results of content and distribution of protein and amino acids in different depth of lake sediments can used to explain regulation of protein decomposition, potential environment effects of stored nitrogen in proteir, effects of amino acids as nutrition resource to microbes, and lake environmental effects of nitrogen in amino acids. 4. Existent state of protein and DNA is studied. Based on the characteristics of their combine with inorganic minerals which can enhance their stability, we discussed their preserving in geological environment and a new idea and method of extracting. 5. Research results of content, distribution and change of DNA, RNA and nucleotides in lake sediments explain temporal and spatial change regulation of genetic materials. Study on molecular phylogeny of DNA is a new and available method to identify microbe communities. Finding and using of the methods for special DNA segment amplifying in vitro and identifying in sediments of lake Erhai is starting for research of organisms in lake sediments. Study on eubacteira has showed their coupling relations with biogeechemical cycles. They are concerned with iron and manganese redox and nitrogen cycles. We have explained primarily microbe mechanism of these cycles and given some new explaining in point of view of microbe actions for some chemical research results. 6. Distribution of microbes in lake sediments is effected by multi-factors, such as oxygen content, pH, redox potential, temperature and nutrition resource content, quality and proportion of nutrition materials effects growth and vanish of microbe communities. Ratio of C and N of biological molecules is low relatively, so they are variable organic matter and high quality resources of nutrition. We have brought forward to a new classified method of organic matter and explained its advantages and environmental meaning. 7. We have put forward to a point of view that protein is temporary existing form of sulfur. Protein is a hinge of transforming from organic sulfur to inorganic sulfur or in reverse. The process is finished by composition and decomposition of protein. Sulfur cycle in lake sediments is a process in multi-routes and participating of different forms of sulfur. Microbes and their metabolism is biological mechanism of sulfur cycles. There are a lot of varieties of microbes whose metabolism and electron transfer pathway is multiple. 8. Cycles of carbon, nitrogen, sulfur, iron and manganese is relation to changes of biological macromolecules and decomposition of organic matter. Microbes are main factor of the processes, and their varieties and distribution are alterable and regulated by many factors.
页数	102
语种	中文
文献类型	学位论文
条目标识符	http://ir.gyig.ac.cn/handle/352002/3572
专题	研究生_研究生_学位论文环境地球化学国家重点实验室
推荐引用方式 GB/T 7714	梁小兵. 湖泊沉积物中生物大分子的研究[D]. 中国科学院地球化学研究所. 中国科学院地球化学研究所,2001.

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