Biotechnology, Department of Chemistry, Center for Chemistry & Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden; Laboratórios de Desenvolvimento de Bioprocessos, Departamento de Engenharia Bioquímica, Escola de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21949-900, Brazil.
Product Development, Department of Design Sciences, Lund University, Box 118, SE-221 00 Lund, Sweden.
Bioresour Technol. 2018 Feb;249:777-782. doi: 10.1016/j.biortech.2017.10.087. Epub 2017 Nov 12.
This study uses three-dimensional (3D) printing technology as a tool for designing carriers for immobilization of microbial cells for bioprocesses. Production of propionic acid from glucose by immobilized Propionibacterium sp. cells was studied as a model system. For cell adsorption, the 3D-printed nylon beads were added to the culture medium during 3 rounds of cell cultivation. Cell adsorption and fermentation kinetics were similar irrespective of the bead size and lattice structure. The cells bound to 15 mm beads exhibited reduced fermentation time as compared to free cell fermentations; maximum productivity and propionic acid titer of 0.46 g/L h and 25.8 g/L, respectively, were obtained. Treatment of the beads with polyethyleneimine improved cell-matrix binding, but lowered the productivity perhaps due to inhibitory effect of the polycation. Scanning electron micrographs revealed the cells to be located in crevices of the beads, but were more uniformly distributed on PEI-coated carrier indicating charge-charge interaction.
本研究以三维（3D）打印技术为工具，设计用于固定微生物细胞的载体，用于生物工艺。以固定化丙酸杆菌细胞从葡萄糖生产丙酸作为模型系统进行研究。对于细胞吸附，在 3 轮细胞培养期间将 3D 打印的尼龙珠添加到培养基中。无论珠的大小和晶格结构如何，细胞吸附和发酵动力学都相似。与游离细胞发酵相比，与 15mm 珠结合的细胞表现出缩短的发酵时间；分别获得 0.46g/L·h 的最大生产力和 25.8g/L 的丙酸浓度。用聚乙烯亚胺处理珠子可改善细胞-基质结合，但降低生产力，可能是由于聚阳离子的抑制作用。扫描电子显微镜图像显示细胞位于珠子的缝隙中，但在 PEI 涂层载体上更均匀地分布，表明电荷-电荷相互作用。
