Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, D-37077 Göttingen, Germany.
Soft Matter. 2019 Apr 3;15(14):3027-3035. doi: 10.1039/c8sm02236d.
The initial stages of biofilm formation at a surface are triggered by the surface association of individual microorganisms. The biological mechanisms and interfacial interactions underlying microbial adhesion to surfaces have been widely studied for bacteria, while microalgae remained rather unconsidered despite their technological relevance, e.g., in photo-bioreactors. We performed in vivo micropipette force measurements with the model organism Chlamydomonas reinhardtii, a unicellular eukaryotic microalga that dwells in liquid-infused soils and on moist rocks. We characterize the adhesion forces and dissect the influence of intermolecular interactions by probing the adhesion forces of single cells on different model substrates with tailored properties. Our experiments show that the flagella-mediated adhesion of Chlamydomonas to surfaces is largely substrate independent, enabling the cell to adhere to any type of surface. This universal adhesion mechanism allows the microalga to effectively colonize abiotic surfaces in their heterogeneous natural habitats. Our results reveal a dominant contribution of electrostatic interactions governing microalgal adhesion and suggest that flagella membrane processes may cause significant variations of the adhesive properties of the flagella.
生物膜在表面的初始形成阶段是由单个微生物与表面的关联触发的。微生物附着在表面的生物机制和界面相互作用已经被广泛研究，例如在细菌方面，而微藻则被忽视了，尽管它们在技术上具有相关性，例如在光生物反应器中。我们使用模式生物莱茵衣藻进行了体内微量移液器力测量，莱茵衣藻是一种生活在液体浸润土壤和潮湿岩石上的单细胞真核微藻。我们通过探测单个细胞在不同具有定制特性的模型基底上的粘附力来表征粘附力并剖析分子间相互作用的影响。我们的实验表明，衣藻通过鞭毛介导的与表面的粘附在很大程度上与基底无关，使细胞能够粘附在任何类型的表面上。这种通用的粘附机制使微藻能够有效地在其异质的自然栖息地中定殖于非生物表面。我们的结果揭示了控制微藻粘附的静电相互作用的主要贡献，并表明鞭毛膜过程可能导致鞭毛的粘附特性发生显著变化。
