Rawindran Hemamalini, Syed Rabbani, Alangari Abdulaziz, Khoo Kuan Shiong, Lim Jun Wei, Sahrin Nurul Tasnim, Suparmaniam Uganeeswary, Raksasat Ratchaprapa, Liew Chin Seng, Leong Wai Hong, Kiatkittipong Worapon, Shahid Muhammad Kashif, Hara Hirofumi, Shaharun Maizatul Shima
HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak Darul Ridzuan, Malaysia.
Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
Environ Res. 2023 Apr 1;222:115352. doi: 10.1016/j.envres.2023.115352. Epub 2023 Jan 27.
The capacity to maximize the proliferation of microalgal cells by means of topologically textured organic solid surfaces under various pH gave rise to the fundamental biophysical analysis of cell-surface attachment in this study. The substrate used in analysis was palm kernel expeller (PKE) in which the microalgal cells had adhered onto its surface. The findings elucidated the relevance of surface properties in terms of surface wettability and surface energy in relation to the attached microalgal growth with pH as the limiting factor. The increase in hydrophobicity of PKE-microalgae attachment was able to facilitate the formation of biofilm better. The pH 5 and pH 11 were found to be the conditions with highest and lowest microalgal growths, respectively, which were in tandem with the highest contact angle value at pH 5 and conversely for pH 11. The work of attachment (W) had supported the derived model with positive values being attained for all the pH conditions, corroborating the thermodynamic feasibility. Finally, this study had unveiled the mechanism of microalgal attachment onto the surface of PKE using the aid of extracellular polymeric surfaces (EPS) from microalgae. Also, the hydrophobic nature of PKE enabled excellent attachment alongside with nutrients for microalgae to grow and from layer-by-layer (LbL) assembly. This assembly was then isolated using organosolv method by means of biphasic solvents, namely, methanol and chloroform, to induce detachment.
在不同pH值条件下，通过拓扑结构的有机固体表面使微藻细胞增殖最大化的能力引发了本研究中细胞表面附着的基础生物物理分析。分析中使用的底物是棕榈仁粕（PKE），微藻细胞已附着在其表面。研究结果阐明了表面性质在表面润湿性和表面能方面与附着微藻生长的相关性，其中pH值是限制因素。PKE - 微藻附着疏水性的增加能够更好地促进生物膜的形成。发现pH 5和pH 11分别是微藻生长最高和最低的条件，这与pH 5时最高的接触角值一致，而pH 11时则相反。附着功（W）支持了推导模型，在所有pH条件下均获得正值，证实了热力学可行性。最后，本研究借助微藻的细胞外聚合物表面（EPS）揭示了微藻附着在PKE表面的机制。此外，PKE的疏水性使其能够实现良好的附着，并为微藻生长提供营养，从而实现逐层（LbL）组装。然后通过双相溶剂甲醇和氯仿采用有机溶剂法分离这种组装体以诱导分离。
