Zhang Zhiyu, Boccazzi Paolo, Choi Hyun-Goo, Perozziello Gerardo, Sinskey Anthony J, Jensen Klavs F
Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave. 66-566, Cambridge, MA 02139, USA.
Lab Chip. 2006 Jul;6(7):906-13. doi: 10.1039/b518396k. Epub 2006 Apr 20.
In a chemostat, microbial cells reach a steady state condition at which cell biomass production, substrates and the product concentrations remain constant. These features make continuous culture a unique and powerful tool for biological and physiological research. We present a polymer-based microbioreactor system integrated with optical density (OD), pH, and dissolved oxygen (DO) real-time measurements for continuous cultivation of microbial cells. Escherichia coli (E. coli) cells are continuously cultured in a 150 microL, membrane-aerated, well-mixed microbioreactor fed by a pressure-driven flow of fresh medium through a microchannel. Chemotaxisial back growth of bacterial cells into the medium feed channel is prevented by local heating. Using poly(ethylene glycol) (PEG)-grafted poly(acrylic acid) (PAA) copolymer films, the inner surfaces of poly(methyl methacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS) of the microbioreactor are modified to generate bio-inert surfaces resistant to non-specific protein adsorption and cell adhesion. The modified surfaces of microbioreactor effectively reduce wall growth of E. coli for a prolonged period of cultivation. Steady state conditions at different dilution rates are demonstrated and characterized by steady OD, pH, and DO levels.
在恒化器中，微生物细胞达到一种稳态条件，此时细胞生物量的产生、底物和产物浓度保持恒定。这些特性使连续培养成为生物学和生理学研究中一种独特而强大的工具。我们展示了一种基于聚合物的微生物反应器系统，该系统集成了光密度（OD）、pH值和溶解氧（DO）实时测量功能，用于微生物细胞的连续培养。大肠杆菌（E. coli）细胞在一个150微升、膜曝气、充分混合的微生物反应器中连续培养，新鲜培养基通过微通道由压力驱动流动供给。通过局部加热防止细菌细胞向培养基进料通道的趋化性反向生长。使用聚（乙二醇）（PEG）接枝的聚（丙烯酸）（PAA）共聚物薄膜，对微生物反应器的聚（甲基丙烯酸甲酯）（PMMA）和聚（二甲基硅氧烷）（PDMS）的内表面进行改性，以产生抗非特异性蛋白质吸附和细胞粘附的生物惰性表面。微生物反应器的改性表面在长时间培养中有效减少了大肠杆菌的壁生长。展示了不同稀释率下的稳态条件，并通过稳定的OD、pH值和DO水平进行了表征。
