Magnetic resonance imaging of biofilm mass transport processes with gadolinium tracers

使用钆示踪剂对生物膜传质过程进行磁共振成像

• 批准号: EP/G028443/1
• 负责人: Vernon Phoenix
• 金额: $ 29.48万
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG028443%2F1
• 关键词: Magnetic; resonance; imaging; biofilm; mass

Biofilms are dense cities of bacteria which adhere together by excreting a slimy, glue-like substance. Significantly, these slimy communities offer huge potential in an array of important biotechnological applications, such as sewage treatment, biofuel production and the generation of electricity in microbial fuel cells. They also play an important role in controlling the chemistry of the natural environment. For a biofilm to function, however, reactants (e.g. the sewage in sewage treatment plants) must be efficiently transported through the biofilm where they are processed by bacteria. Significantly, the rate at which the biofilm can operate is controlled by the rate at which these reactants move through the biofilm. Consequently, it is vital for engineers and microbiologists to be able to measure the rate of reactant supply. Critically, this data is essential to our understanding of the way biofilms work and our ability to enhance biofilm performance. Whilst tools for measuring transport in biofilms exist, they cannot measure all the parameters needed (for example, some are restricted to either high or low molecular mass reactants) and some are invasive, potentially damaging the biofilm, altering results. Magnetic resonance imaging (MRI), however, has tremendous potential to bridge this technology gap. MRI is non-invasive and so it quite literally enables us to look inside the biofilm and measure the movement of reactants without harming the biofilm in any way. Problematically, while MRI can measure the movement of water in biofilms (which can be used as a proxy for the movement of other low molecular mass compounds), measurement of high molecular mass molecules is difficult. This, however, can change. By labeling these molecules with a paramagnetic ion (in this case gadolinium), the molecule suddenly becomes easily visible with MRI. This technology is already applied in clinical research, where gadolinium is used to make molecules readily visible in human and other mammalian tissues. Here, we aim to demonstrate that paramagnetically labeled molecules can be used to track mass transport within biofilms. In this investigation, we will image the transport of a range of commercially available gadolinium labeled molecules in biofilms from laboratory wastewater treatment bioreactors and from natural systems. A calibration protocol will used to convert MRI data into actual gadolinium concentrations, enabling us to determine the concentration of Gd in each image pixel at each time interval. From this, diffusion coefficients for each gadolinium labeled molecule in each biofilm will be calculated. A 3D model will also be used the generate maps of diffusion coefficients throughout each biofilm. If successful, this technology would be an invaluable tool providing microbiologists and engineers alike with essential transport data needed to harness the full power of these complex biological communities.

生物膜是细菌的密集城市，它们通过分泌一种粘糊糊的、类似胶水的物质粘附在一起。值得注意的是，这些黏糊糊的群落在一系列重要的生物技术应用中提供了巨大的潜力，例如污水处理、生物燃料生产和微生物燃料电池发电。它们在控制自然环境的化学方面也发挥着重要作用。然而，为了使生物膜发挥作用，反应物（例如污水处理厂中的污水）必须有效地通过生物膜运输，在生物膜中它们被细菌处理。值得注意的是，生物膜可以操作的速率由这些反应物移动通过生物膜的速率控制。因此，对于工程师和微生物学家来说，能够测量反应物供应速率至关重要。至关重要的是，这些数据对于我们理解生物膜的工作方式以及我们提高生物膜性能的能力至关重要。虽然存在用于测量生物膜中的运输的工具，但它们不能测量所需的所有参数（例如，一些被限制为高分子量或低分子量反应物），并且一些是侵入性的，可能破坏生物膜，改变结果。然而，磁共振成像（MRI）具有弥合这一技术差距的巨大潜力。MRI是非侵入性的，因此它确实使我们能够查看生物膜内部并测量反应物的运动，而不会以任何方式损害生物膜。问题是，虽然MRI可以测量生物膜中的水的运动（其可以用作其他低分子量化合物的运动的代表），但是测量高分子量分子是困难的。然而，这是可以改变的。通过用顺磁离子（在这种情况下是钆）标记这些分子，分子突然变得很容易用MRI看到。这项技术已经应用于临床研究，钆用于使分子在人类和其他哺乳动物组织中容易可见。在这里，我们的目标是证明顺磁性标记的分子可以用来跟踪生物膜内的质量传输。在这项调查中，我们将图像的运输范围内的商业可用的钆标记的分子在生物膜从实验室废水处理生物反应器和自然系统。校准协议将用于将MRI数据转换为实际钆浓度，使我们能够确定每个时间间隔内每个图像像素中的Gd浓度。由此，将计算每个生物膜中每个钆标记分子的扩散系数。还将使用3D模型来生成遍及每个生物膜的扩散系数的图。如果成功，这项技术将成为一个宝贵的工具，为微生物学家和工程师提供利用这些复杂生物群落的全部力量所需的基本运输数据。

项目成果

Magnetic resonance imaging of mass transport and structure inside a phototrophic biofilm.

光养生物膜内的质量传输和结构的磁共振成像。

• DOI: 10.1007/s00284-012-0292-3
• 发表时间: 2013
• 期刊: Current microbiology
• 影响因子: 2.6
• 作者: Ramanan B

Application of paramagnetically tagged molecules for magnetic resonance imaging of biofilm mass transport processes.

顺磁标记分子在生物膜传质过程磁共振成像中的应用。

• DOI: 10.1128/aem.03016-09
• 发表时间: 2010
• 期刊: Applied and environmental microbiology
• 影响因子: 4.4
• 作者: Ramanan B

Characterization of nanoparticle transport through quartz and dolomite gravels by magnetic resonance imaging

通过磁共振成像表征纳米粒子通过石英和白云石砾石的传输

• DOI: 10.1007/s13762-015-0767-4
• 发表时间: 2015
• 期刊: International Journal of Environmental Science and Technology
• 影响因子: 3.1
• 作者: Lakshmanan S

Nanoparticle transport in saturated porous medium using magnetic resonance imaging

使用磁共振成像在饱和多孔介质中纳米粒子的传输

• DOI: 10.1016/j.cej.2014.12.076
• 发表时间: 2015
• 期刊: Chemical Engineering Journal
• 影响因子: 15.1
• 作者: Lakshmanan S