Grumbein S, Opitz M, Lieleg O
Zentralinstitut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.
Metallomics. 2014 Aug;6(8):1441-50. doi: 10.1039/c4mt00049h.
Many problems caused by bacterial biofilms can be traced back to their high resilience towards chemical perturbations and their extraordinary sturdiness towards mechanical forces. However, the molecular mechanisms that link the mechanical properties of a biofilm with the ability of bacteria to survive in different chemical environments remain enigmatic. Here, we study the erosion stability of Bacillus subtilis (B. subtilis) biofilms in the presence of different chemical environments. We find that these biofilms can utilize the absorption of certain metal ions such as Cu(2+), Zn(2+), Fe(2+), Fe(3+) and Al(3+) into the biofilm matrix to avoid erosion by shear forces. Interestingly, many of these metal ions are toxic for planktonic B. subtilis bacteria. However, their toxic activity is suppressed when the ions are absorbed into the biofilm matrix. Our experiments clearly demonstrate that the biofilm matrix has to fulfill a dual function, i.e. regulating both the mechanical properties of the biofilm and providing a selective barrier towards toxic chemicals.
由细菌生物膜引起的许多问题可追溯到它们对化学扰动的高弹性以及对机械力的非凡坚固性。然而，将生物膜的机械性能与细菌在不同化学环境中生存能力联系起来的分子机制仍然是个谜。在这里，我们研究了在不同化学环境下枯草芽孢杆菌生物膜的侵蚀稳定性。我们发现这些生物膜可以利用某些金属离子如Cu(2+)、Zn(2+)、Fe(2+)、Fe(3+)和Al(3+)吸收到生物膜基质中，以避免受到剪切力的侵蚀。有趣的是，这些金属离子中的许多对浮游的枯草芽孢杆菌具有毒性。然而，当这些离子被吸收到生物膜基质中时，它们的毒性活性就会受到抑制。我们的实验清楚地表明，生物膜基质必须履行双重功能，即调节生物膜的机械性能并对有毒化学物质提供选择性屏障。
