权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Quantification and characterisation of the aerobic degradation of organic-walled dinoflagellate cysts

有机壁甲藻包囊需氧降解的定量和表征

基本信息

批准号：
248465837
负责人：
Professorin Dr. Karin Zonneveld
金额：
--
依托单位：
Fachgebiet Forschungsprofessur - Meeresgeologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/248465837?language=en
关键词：
Quantification characterisation aerobic degradation organic

项目摘要

Organic walled dinoflagellate cysts are taxonomically well defined kerogen particles that show large species specific variation in their vulnerability to early diagenetic aerobic degradation. As representative of organic matter particles with differential lability, this makes them useful to study particulate organic matter degradation processes. As they are used both in industry and in academia as tools to reconstruct palaeoenvironment, palaeoceanography and determine the stratigraphy of marine archives it is essential to gain information about the process of degradation and its controlling factors. In this study we aim to enlarge this information by quantifying the species specific degradation rates in relationship with oxygen concentrations and to determine the biologic (microbial) and/or chemical character of the degradation process. This information can form the basis for a method to quantify past bottom/pore water oxygen concentrations from sedimentary archives. Apart from this we will investigate if cyst degradation is influenced by differences in the amount and composition of organic matter of differential lability in the ambient sedimentary environment. For this we will study the degradation process of the dinoflagellate cysts in a laboratory and field experiments under controlled redox conditions as well as in downcore studies. In the laboratory experiment, sediments with a known cysts composition will be incubated under oxic and anoxic conditions. Material for these experiments is derived from two high productivity regime sites with anoxic bottom waters (eastern Arabian Sea, off NW Africa) and two low productivity regime sites (central eastern Mediterranean discovery basin brine (anoxic) and sediments of the basin margin (oxic). In the field experiment, autoclaved sediments from the Arabian sea oxygen minimum zone with a known cyst composition have been partitioned and transferred to bags composed of dialysis membrane (microbe tight but diffusible for oxygen) and polycarbonate gaze with a pore size of 5 mu-m (penetration of both microbes and oxygen). The material has been exposed to oxic, suboxic and hypoxic natural environments for five years in different water masses of which the oxygen contend is known or monitored. Aliquots of these sediments have been harvested once a year from 2008 to 2013. For determination of the relationship between pore water oxygen concentrations and degradation rates of dinoflagellate cysts in subsurface sediments, the downcore alteration in cyst concentration and association composition in multicore sediments from the Eastern Mediterranean Discovery Basin brine system and the oxygen minimum zones of the Arabian Sea and off NW Africa will be compared to already known oxygen concentrations in pore waters. Furthermore the degradation will be studies along pore water oxygen gradients related to downward and upward moving oxidation fronts in multi and gravity cores of the Discovery Basin region.

有机壁甲藻孢囊是分类学上定义明确的干酪根颗粒，其在早期成岩有氧降解的脆弱性方面表现出较大的物种特异性变化。作为具有微分不稳定性的有机物颗粒的代表，这使得它们可以用于研究颗粒有机物的降解过程。由于工业界和学术界都将其用作重建古环境、古海洋学和确定海洋档案地层的工具，因此必须获得关于退化过程及其控制因素的信息。在这项研究中，我们的目标是扩大这一信息，通过量化的物种特定的降解速率与氧浓度的关系，并确定生物（微生物）和/或化学特性的降解过程。这些信息可以形成一种方法的基础，以量化过去的底部/孔隙水氧浓度从沉积档案。除此之外，我们还将研究包囊降解是否受到周围沉积环境中差异不稳定性有机物的数量和组成差异的影响。为此，我们将研究甲藻孢囊的降解过程中的实验室和现场实验控制氧化还原条件下，以及在downcore研究。在实验室实验中，将在好氧和缺氧条件下培养具有已知孢囊组成的沉积物。这些实验的材料来自两个具有缺氧底层沃茨的高生产力状态站点（阿拉伯海东部，非洲西北部海域）和两个低生产力状态站点（地中海发现盆地的中东部盐水（缺氧）和盆地边缘的沉积物（好氧））。在现场实验中，来自阿拉伯海氧气最小区的具有已知囊组成的高压灭菌沉积物已被分区并转移到由透析膜（微生物密封但氧气可扩散）和孔径为5 μ m（微生物和氧气均可渗透）的聚碳酸酯凝视组成的袋中。该材料在已知或监测氧含量的不同水体中暴露于含氧、亚氧和低氧的自然环境中五年。从2008年到2013年，每年采集一次这些沉积物的等分试样。为了确定孔隙水氧浓度和地下沉积物中甲藻孢囊降解速率之间的关系，将对东地中海发现盆地卤水系统和阿拉伯海和非洲西北部海域的最低含氧区的多核沉积物中孢囊浓度和缔合物组成的底层改变与已知的孔隙沃茨中的氧浓度进行比较。此外，还将研究发现盆地区域多岩心和重力岩心中与向下和向上移动的氧化前沿相关的沿着孔隙水氧梯度的降解情况。