School of Materials Science and Engineering, Ocean University of China, Qingdao, 266100, China.
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Colloids Surf B Biointerfaces. 2021 Mar;199:111522. doi: 10.1016/j.colsurfb.2020.111522. Epub 2020 Dec 13.
Biofilm attached cultivation is a promising method for efficient production of microalgae. Determining the surface property index to select an appropriate substrate benefiting the algae adhesion and biofilm formation is very important for the cultivation method. This work focused on elucidating and quantifying the influence of surface wettability and roughness of substrate on Chlorella vulgaris adhesion. Firstly, surface modified styrene-acrylic (SA) resin films by adding different dosage of perfluoroalkyl ethyl acrylate (FM) were prepared. Property characterization shows that the surface contact angle in water, formamide and diiodomethane of FM modified SA films is significantly associated with the FM dosage, while the other surface properties including zeta potential, surface potential and surface roughness have insignificant difference. The calculated surface free energy parameters show that the SA films belong to the non-polar substrata. A well quantitative correlation that the adhesion capacity of C. vulgaris linearly declines with the increase of water contact angle was obtained. And a near linear relationship between the adhesion capacity and the surface free energy (γ), or the cohesion free energy (ΔG) was also observed. Secondly, the surface roughness solely changed SA films were prepared by replicating the morphology of stainless steel sieves through the PDMS template method. The patterned SA films have alternately arranged rectangular "valleys" and "ridges". A well linear correlation between the microalgae adhesion capacity and the surface roughness was also obtained.
生物膜附着培养是一种高效生产微藻的有前途的方法。确定表面性质指数以选择有利于藻类附着和生物膜形成的合适基质对于培养方法非常重要。本工作重点阐明和量化基质表面润湿性和粗糙度对普通小球藻附着的影响。首先，通过添加不同剂量的全氟辛基乙基丙烯酸酯（FM）制备了表面改性的苯乙烯-丙烯酸（SA）树脂膜。性能表征表明，FM 改性 SA 膜在水中、甲酰胺和二碘甲烷中的表面接触角与 FM 剂量显著相关，而其他表面性质，包括动电位、表面电位和表面粗糙度没有显著差异。计算得到的表面自由能参数表明，SA 膜属于非极性基质。得到了普通小球藻的附着能力随水接触角的增加呈线性下降的良好定量关系。并且还观察到附着能力与表面自由能（γ）或内聚自由能（ΔG）之间存在近似线性关系。其次，通过 PDMS 模板法复制不锈钢筛网的形貌来制备仅改变表面粗糙度的 SA 膜。图案化的 SA 膜具有交替排列的矩形“山谷”和“山脊”。也得到了微藻附着能力与表面粗糙度之间的良好线性关系。
