Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT 59717, USA.
Biotechnol Bioeng. 2013 May;110(5):1366-75. doi: 10.1002/bit.24803. Epub 2012 Dec 29.
Biofilm growth in porous media is difficult to study non-invasively due to the opaqueness and heterogeneity of the systems. Magnetic resonance is utilized to non-invasively study water dynamics within porous media. Displacement-relaxation correlation experiments were performed on fluid flow during biofilm growth in a model porous media of mono-dispersed polystyrene beads. The spin-spin T2 magnetic relaxation distinguishes between the biofilm phase and bulk fluid phase due to water-biopolymer interactions present in the biofilm, and the flow dynamics are measured using PGSE NMR experiments. By correlating these two measurements, the effects of biofilm growth on the fluid dynamics can be separated into a detailed analysis of both the biofilm phase and the fluid phase simultaneously within the same experiment. Within the displacement resolution of these experiments, no convective flow was measured through the biomass. An increased amount of longitudinal hydrodynamic dispersion indicates increased hydrodynamic mixing due to fluid channeling caused by biofilm growth. The effect of different biofilm growth conditions was measured by varying the strength of the bacterial growth medium.
由于系统的不透明性和异质性，多孔介质中的生物膜生长很难进行非侵入性研究。磁共振被用于非侵入性地研究多孔介质内的水动力。在模型多孔介质中单分散聚苯乙烯珠中进行生物膜生长期间的流体流动进行了弛豫相关实验。自旋-自旋 T2 磁弛豫由于生物膜中存在水-生物聚合物相互作用而区分生物膜相与体相流体相，并且使用 PGSE NMR 实验测量流动动力学。通过将这两个测量值相关联，可以将生物膜生长对流体动力学的影响分离为在同一实验中同时对生物膜相和流体相进行详细分析。在这些实验的位移分辨率内，没有通过生物质测量到对流流。由于生物膜生长引起的流体通道化，增加的纵向流体力学弥散度表明增加了流体混合。通过改变细菌生长培养基的强度来测量不同生物膜生长条件的影响。
