Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
Faraday Discuss. 2019 Oct 30;219(0):58-72. doi: 10.1039/c9fd00019d.
Herein, we describe a method to produce yeast-laden hydrogel inks for the direct-write 3D printing of cuboidal lattices for immobilized whole-cell catalysis. A poly(alkyl glycidyl ether)-based triblock copolymer was designed to have three important features for this application: (1) a temperature response, which allowed for facile processing of the material; (2) a shear response, which facilitated the extrusion of the material through a nozzle; and (3) UV light induced polymerization, which enabled the post-extrusion chemical crosslinking of network chains, and the fabrication of robust printed objects. These three key stimuli responses were confirmed via rheometrical characterization. A genetically-engineered yeast strain with an upregulated α-factor production pathway was incorporated into the hydrogel ink and 3D printed. The immobilized yeast cells exhibited adequate viability of 87.5% within the hydrogel. The production of the upregulated α-factor was detected using a detecting yeast strain and quantified at 268 nM (s = 34.6 nM) over 72 h. The reusability of these bioreactors was demonstrated via immersion of the yeast-laden hydrogel lattice in fresh SC media and confirmed by the detection of similar amounts of upregulated α-factor at 259 nM (s = 45.1 nM). These yeast-laden materials represent an attractive opportunity for whole-cell catalysis of other high-value products in a sustainable and continuous manner.
在这里，我们描述了一种生产载有酵母的水凝胶墨水的方法，用于直接写入 3D 打印用于固定化全细胞催化的立方格子。设计了一种基于聚（烷基缩水甘油醚）的三嵌段共聚物，具有三个适用于该应用的重要特征：（1）温度响应，使材料易于加工；（2）剪切响应，便于通过喷嘴挤出材料；（3）UV 光引发聚合，使网络链的后挤出化学交联和制造坚固的打印物体成为可能。通过流变学特性研究证实了这三个关键刺激响应。将具有上调α因子生产途径的基因工程酵母菌株掺入水凝胶墨水中并进行 3D 打印。固定化酵母细胞在水凝胶中保持 87.5%的足够活力。使用检测酵母菌株检测到上调的α因子的产生，并在 72 小时内定量为 268 nM（s = 34.6 nM）。通过将载有酵母的水凝胶格子浸入新鲜 SC 培养基中并通过检测到类似数量的 259 nM（s = 45.1 nM）的上调α因子来证明这些生物反应器的可重复使用性。这些载有酵母的材料为以可持续和连续的方式对其他高价值产品进行全细胞催化提供了一个有吸引力的机会。
