METAL SEQUESTERING BY MICROORGANISMS IN AND FROM AQUATIC ENVIRONMENTS

水生环境中微生物的金属螯合

• 批准号: 6107361
• 负责人: THOMAS E JENSEN
• 金额: --
• 依托单位: HERBERT H. LEHMAN COLLEGE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6107361
• 关键词: X ray microscopy; alternatives to animals in research; atomic absorption spectrometry; bacteria; heavy metals; microorganism metabolism; scanning electron microscopy; trace elements; transmission electron microscopy; water environment; water pollution

The present proposal represents an expanded effort of that undertaken in the 1992-93 FY, which was entitled "Investigation of trace metal sequestering by polyphosphate bodies in picoplankton." We will now focus on the various mechanisms by which trace and heavy metals are taken up and immobilized within the microbial consortium that are found in the natural aquatic environments. Our approach will be to employ the transmission electron microscope in conjunction with X-ray energy dispersive analysis (EDX), to study bacterial-sized cells and their associated non-cellular particulates. This qualitative and semi-quantitative approach will enable us to analyze cells and cell constituents for their elemental content, and make it possible for us to localize regions in which metal ions become concentrated. Our study over the past year has been fruitful as training ground as we now undertake examination of more complex natural aquatic systems. We will attempt to isolate additional numerically important, metal immobilizing species and study their propensity for metal uptake. We will examine metal polluted aquatic sediments for bacteria and associated particulates, important heavy metal bearing activated sludge and attempt to localize accumulated metals in or on cells making up the biomass. Pure cultures that take up and concentrate a heavy metal have great potential value in the study of mechanisms involved but they also may be developed for use in aspects of water purification, valuable metal recovery or other practical uses. Of greater importance from an environmental standpoint is the fact that a heavy metal can be tracked from a sediment into a bacterial cell mass using the EM-EDX system. Many of the bacteria can also serve as a food supply for grazing protozoa and other invertebrate animals. Our effort in the present proposal will lay a groundwork for these kinds of studies.

本提案代表了在 1992 - 93年的FY，标题为“痕量金属的研究 picoplankton中的多磷酸物体隔离。“我们现在将集中精力 在各种机制上，痕迹和重金属被占用和 固定在自然中的微生物联盟中 水生环境。 我们的方法是采用传输 电子显微镜与X射线能量色散分析结合 （EDX），研究细菌大小的细胞及其相关的非细胞 颗粒。 这种定性和半定量的方法将实现 我们分析细胞和细胞成分的元素含量，以及 使我们可以定位金属离子成为的区域 集中。 在过去的一年中，我们的研究在培训中富有成果 我们现在对更复杂的天然水生的检查进行地面检查 系统。 我们将尝试隔离其他数值重要的， 金属固定物种并研究其对金属摄取的倾向。 我们将检查金属污染细菌和 相关的颗粒，重要的重金属轴承激活污泥 并尝试将累积的金属定位在组成的细胞中或在细胞中 生物量。 占用并集中重金属的纯文化具有 在研究涉及机制的研究中的巨大潜在价值，但它们也 可以开发用于水净化方面，有价值的金属 恢复或其他实际用途。 从一个 环境角度是可以跟踪重金属的事实 使用EM-EDX系统从沉积物进入细菌细胞质量。 许多 细菌的菜还可以作为放牧原生动物的食物供应 其他无脊椎动物。 我们在本提案中的努力将提出 这类研究的基础。