Department of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Biotechnol Adv. 2019 Nov 1;37(6):107365. doi: 10.1016/j.biotechadv.2019.03.004. Epub 2019 Mar 6.
Downstream is a very expensive process for microbial fermentation. It usually involves complicated equipment and processes to obtain desired chemicals or materials from intra- or/and extracellular spaces of microorganisms. Recently, it becomes possible to simplify the microbial cell separation processes by morphologically engineering the shapes of small microorganisms. Cells can be induced aggregated, or enlarged into fibers or large spheres, so that gravity sedimentation or press filtration becomes a convenient operation. Various genes related to the microbial morphology have been manipulated to obtain large shapes and multiple fission to form long fibers or large spheres. At the same time, induced lysis of cells can be achieved by introducing lysis gene into the cells. To achieve better economy, it is desirable to receive products both in broths and in cell masses. Co-production of different chemicals produced intracellularly and extracellularly could be an effectively economical way. Based on these novel methods, easy cell separation in the downstream processing is expected to be achieved soon.
下游处理对于微生物发酵来说是一个非常昂贵的过程。通常需要复杂的设备和工艺，才能从微生物的胞内或/和胞外空间中获得所需的化学物质或材料。最近，通过对小微生物的形态进行工程设计，使得微生物细胞的分离过程得以简化。可以诱导细胞聚集，或使细胞增大成为纤维或大球体，从而使重力沉降或压滤成为一种方便的操作。已经操纵了各种与微生物形态相关的基因，以获得大的形状和多次分裂，从而形成长纤维或大球体。同时，可以通过向细胞中引入裂解基因来实现细胞的诱导裂解。为了获得更好的经济效益，最好能在发酵液和细胞团中同时获得产物。胞内和胞外同时生产不同的化学物质是一种有效的经济方式。基于这些新方法，预计很快就能实现下游处理中简单的细胞分离。
