The Adsorption Mechanism Of Barnacles On The Surface

With the development and utilization of marine resources,marine biological fouling caused more and more serious loss,on the prevention and control of marine biological fouling research has broad prospects for development.The barnacles are a kind of marine fouling organisms which are more destructive.Therefore,the research on the mechanism of the control of the barnacles is one of the most important issues.We demonstrate with the barnacle that the base adopts a unique,disc saw-like geometry,densely perforated with radial microchannels that are intelligently built by the animal to enhance adhesion probably by a crack-trapping mechanism.Meanwhile,the base is shown to be constructed of intergrown calcitic microcrystals with almost no preferred orientation,some varied extent of morphologic change and high level of atomic disorder compared to its geological equivalent.Further,both protein and polysaccharide chemistries are found to be involved in the microstructural development of the base by virtue of their acidic functional groups or confined space,with the latter possibly being dominant in amount.The key microstructural features along with the placement of organic components play crucial roles in the mechanical response of the base to external loads.Our results explain how the barnacle base has been evolutionarily adjusted over different length scales to enhance adhesion.More than 90%of the components of the barnacles are proteins,the attachment of biofouling organism barnacle to underwater surface is guided by an multiprotein complex called cement.The homologous proteins of 19 kDa in the cement of barnacle Megabalanus rosa and the Balanus albicostatus play a crucial role in surface attachment.However,it's interesting to find that they have different isoelectric point?termed Bacp-19 k and Mrcp-19 k;pI=10.3 and 5.8?.In this study E.coli BL21 was utilized to heterologously express these two homologous proteins,followed by Ni affinity purification.The interaction between the purified proteins and silica surface was then investigated by atomic force microscopy and spectroscopic ellipsometry.Our resutls indicated that the absorption morphology of the two homologous proteins were similar at pH=7.4,but their adsorption kinetics are quite different.Meanwhile,it was found that both the attractive force and the plateau adsorption quantity of Mrcp-19 k on SiO₂ surface were much weaker/less than those of Bacp-19 k.