University of California , Davis , California 95616 , United States.
National Bioenergy Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States.
Nano Lett. 2019 Sep 11;19(9):5829-5835. doi: 10.1021/acs.nanolett.9b00066. Epub 2019 Feb 20.
Critical to the success of three-dimensional (3D) printing of living materials with high performance is the development of new ink materials and 3D geometries that favor long-term cell functionality. Here we report the use of freeze-dried live cells as the solid filler to enable a new living material system for direct ink writing of catalytically active microorganisms with tunable densities and various self-supporting porous 3D geometries. Baker's yeast was used as an exemplary live whole-cell biocatalyst, and the printed structures displayed high resolution, large scale, high catalytic activity and long-term viability. An unprecedented high cell loading was achieved, and cell inks showed unique thixotropic behavior. In the presence of glucose, printed bioscaffolds exhibited increased ethanol production compared to bulk counterparts due largely to improved mass transfer through engineered porous structures. The new living materials developed in this work could serve as a versatile platform for process intensification of an array of bioconversion processes utilizing diverse microbial biocatalysts for production of high-value products or bioremediation applications.
对于具有高性能的三维（3D）打印活体材料的成功，开发有利于长期细胞功能的新型墨水材料和 3D 几何形状至关重要。在这里，我们报告了使用冻干活细胞作为固体填充物，以实现一种新的活体材料系统，用于直接写入具有可调密度和各种自支撑多孔 3D 几何形状的催化活性微生物。我们使用面包酵母作为典型的活体全细胞生物催化剂，打印结构显示出高分辨率、大尺寸、高催化活性和长期活力。实现了前所未有的高细胞负载，并且细胞墨水表现出独特的触变性行为。在葡萄糖存在下，打印生物支架由于通过工程多孔结构改善的质量传递，与大块对应物相比表现出增加的乙醇生产。本工作中开发的新型活体材料可以作为一个通用平台，用于利用各种微生物生物催化剂进行的一系列生物转化过程的强化，以生产高价值产品或生物修复应用。
