School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300, Nibong Tebal, Penang, Malaysia.
Microb Ecol. 2023 Jul;86(1):549-562. doi: 10.1007/s00248-022-02091-9. Epub 2022 Aug 18.
Cell adhesion is always the first step in biofilm development. With the emergence of attached cultivation systems, this study aims to promote a cost-effective approach for sustainable cultivation of microalgae, Navicula incerta, by pre-coating the main substrates, commercial polyvinylidene fluoride (PVDF) membranes with its own washed algal cells and self-produced soluble extracellular polymeric substances (EPS) for strengthened biofilm development. The effects of pH value (6 to 9), cell suspension volume (10 to 30 mL), and EPS volume (10 to 50 mL) were statistically optimized by means of response surface methodology toolkit. Model outputs revealed good agreement with cell adhesion data variation less than 1% at optimized pre-coating conditions (7.20 pH, 30 mL cell suspension volume, and 50 mL EPS volume). Throughout long-term biofilm cultivation, results demonstrated that EPS pre-coating substantially improved the attached microalgae density by as high as 271% than pristine PVDF due to rougher surface and the presence of sticky exopolymer particles. Nutrients absorbed via the available EPS coating from the bulk medium made the immobilized cells to release less polysaccharides on an average of 30% less than uncoated PVDF. This work suggests that adhesive polymer binders derived from organic sources can be effectively integrated into the development of high-performance novel materials as biocoating for immobilized microalgae cultivation.
细胞黏附通常是生物膜发展的第一步。随着附着培养系统的出现，本研究旨在通过用自身洗过的藻细胞和自产生的可溶性胞外聚合物（EPS）预先涂覆主要基质（商用聚偏二氟乙烯（PVDF）膜），来促进具有成本效益的、可持续的念珠藻（Navicula incerta）培养方法。通过响应面方法工具箱，对 pH 值（6 到 9）、细胞悬浮液体积（10 到 30 mL）和 EPS 体积（10 到 50 mL）的影响进行了统计学优化。模型输出与细胞黏附数据的变化吻合良好，在优化的预涂覆条件（7.20 pH、30 mL 细胞悬浮液体积和 50 mL EPS 体积）下，差异小于 1%。在长期生物膜培养过程中，结果表明，由于粗糙的表面和粘性的外多聚物颗粒，EPS 预涂覆可使附着的微藻密度提高高达 271%，明显优于原始的 PVDF。由于从主体培养基中通过可用的 EPS 涂层吸收营养物质，固定化细胞平均释放的多糖比未涂覆的 PVDF 少 30%。这项工作表明，源自有机源的粘性聚合物粘合剂可以有效地整合到高性能新型材料的开发中，作为固定化微藻培养的生物涂层。
