Klotz M, Kretschmer M, Goetz A, Ezendam S, Lieleg O, Opitz M
Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-Universität München Munich Germany
Munich School of BioEngineering and Department of Mechanical Engineering, Technische Universität München Garching Germany.
RSC Adv. 2019 Apr 11;9(20):11521-11529. doi: 10.1039/c9ra01955c. eCollection 2019 Apr 9.
Production and secretion of biomolecules can provide new emergent functionalities to the synthesizing organism. In particular, the secretion of extracellular polymeric substances (EPS) by biofilm forming bacteria creates a biofilm matrix that protects the individual bacteria within the biofilm from external stressors such as antibiotics, chemicals and shear flow. Although the main matrix components of biofilms formed by are known, it remains unclear how these matrix components contribute to the erosion stability of biofilms. Here, we combine different biophysical techniques to assess this relation. In particular, we quantify the importance of specific biofilm matrix components on the erosion behavior of biofilms formed by the well-studied NCIB 3610. We find that the absence of biofilm matrix components decreases the erosion stability of NCIB 3610 biofilms in water, largely by abolishing the hydrophobic surface properties of the biofilm and by reducing the biofilm stiffness. However, the erosion resistance of NCIB 3610 biofilms is strongly increased in the presence of metal ions or the antibiotic ciprofloxacin. In the first case, unspecific ionic cross-linking of biofilm components or individual bacteria seems to be responsible for the observed effect, and in the second case there seems to be an unspecific interaction between the antibiotic and the biofilm matrix. Taken together, our results emphasize the importance of the biofilm matrix to reduce biofilm erosion and give insights into how the specific biomolecules interact with certain chemicals to fulfill this task.
生物分子的产生和分泌可为合成生物体提供新的突现功能。特别是，形成生物膜的细菌分泌细胞外聚合物（EPS）会形成一种生物膜基质，保护生物膜内的单个细菌免受抗生素、化学物质和剪切流等外部应激源的影响。尽管已知由[具体细菌名称缺失]形成的生物膜的主要基质成分，但这些基质成分如何影响[具体细菌名称缺失]生物膜的侵蚀稳定性仍不清楚。在这里，我们结合不同的生物物理技术来评估这种关系。特别是，我们量化了特定生物膜基质成分对由经过充分研究的[具体细菌名称缺失]NCIB 3610形成的生物膜侵蚀行为的重要性。我们发现，生物膜基质成分的缺失会降低NCIB 3610生物膜在水中的侵蚀稳定性，这主要是通过消除生物膜的疏水表面特性和降低生物膜的硬度来实现的。然而，在存在金属离子或抗生素环丙沙星的情况下，NCIB 3610生物膜的抗侵蚀性会大大增强。在第一种情况下，生物膜成分或单个细菌的非特异性离子交联似乎是观察到的效果的原因，而在第二种情况下，抗生素与生物膜基质之间似乎存在非特异性相互作用。综上所述，我们的结果强调了生物膜基质对减少生物膜侵蚀的重要性，并深入了解了特定生物分子如何与某些化学物质相互作用来完成这项任务。
