Uniaxial compression measurement device for investigation of the mechanical stability of biofilms
Uniaxial compression measurement device for investigation of the mechanical stability of biofilms
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DOI：
10.1016/s0167-7012(01)00248-2
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发表时间：
2001-07-30
影响因子：
2.2
通讯作者：
Borchard, W
中科院分区：
文献类型：
--
作者：
Körstgens, V;Flemming, HC;Borchard, W
生物膜的机械稳定性对于生物技术是重要的，因为由于生物膜基质的机械故障而导致的生物质的脱落可导致对生物膜过程的严重干扰。在生物结垢的情况下，必须去除生物膜，在这种情况下，必须克服它们的机械稳定性。从单轴压缩实验中获得的表观弹性模量和屈服强度可以作为指示生物膜的机械稳定性的参数。一个薄膜流变仪，它允许确定这些数量，使用模式！在膜过滤器上生长的铜绿假单胞菌的生物膜。在1 μ m s（-1）的压缩速度下记录直至破坏点的压缩应力-应变行为。根据应力-应变曲线，所研究的生物膜可以被描述为粘弹性材料，其表现出塑性流动特性。细胞外聚合物（EPS），保持生物膜在一起，形成一个临时的网络波动的交界点。在屈服点以上，凝胶结构失效，系统表现为高粘性流体。表观弹性模量和屈服点被认为是表征生物膜机械性能的有用参数。(C)2001 Elsevier Science B. V.保留所有权利。
The mechanical stability of biofilms is important for biotechnology, as sloughing of the biomass due to mechanical failure of the biofilm matrix can lead to severe interferences with biofilm processes. In cases of biofouling, biofilms have to be removed, in which case their mechanical stability must be overcome. The apparent modulus of elasticity and the yield strength as obtained from uniaxial compression experiments can be taken as parameters indicative for the mechanical stability of a biofilm. A film rheometer is presented which allows for the determination of these quantities, using mode! biofilms of Pseudomonas aeruginosa grown on membrane filters. The compressive stress-strain behaviour up to the point of failure is recorded at a compression speed of 1 mum s(-1). In accordance with the stress-strain curve, the investigated biofilm can be described as viscoelastic material, which demonstrates plastic flow properties. The extracellular polymeric substances (EPS), which keep biofilms together, form a temporary network of fluctuating junction points. Above the yield point, the gel structure fails and the system behaves as a highly viscous fluid. The apparent modulus of elasticity and the yield point are considered to be useful parameters for characterizing the mechanical properties of biofilms. (C) 2001 Elsevier Science B.V. All rights reserved.