Construction of Yeast Surface Display System and Application in Cellulose Degrading

Cellulose is a low-cost and renewable resource with abundant reserves, but it is difficult to be used because of its compact structure. Currently, the degradation of cellulose requires of cellulases, but the high cost and the difficulty of re-use of free cellulase have limited its wide application. Yeast surface display technology can display multiple cellulase enzymes on the cell surface after being fused with the anchoring protein, so that a yeast surface display cellulase system could be constructed. This system can degrade cellulose efficiently. On the one hand, it has the advantages of surface display, such as easy recycling, good stability, simple operation, and low cost; on the other hand, it can also degrade cellulose into glucose effectively, and has the potential to produce bioethanol by metabolism. The paper summarzes the constrjiction pHnciples of a yeast surface display system, and divides yeast surface displaysystems into direct displaysystems and indirect display systems according to the different anchorng methods of exogenous proteins. The direct display system is that the exogenous protein is directly connected to the cell through the anchor protein. Indirect display systems are linked to cells through exogenous proteins by means of scaffolds. Factors affecting the efficiency of the display system mainly include cell type，anchor protein, scaffold, environmental factors and promoter type. The surface display system consists of GPI system， Pir system and F101 system according to different anchor proteins. The yeast surface display cellulase system can ferment cellulose to produce ethanol， and a lot of progress has been made so far，which provides a reference for the constrjiction of an efficient yeast surface display cellulase system and other multi-enzyme systems. The review describes the constrjiction prnciples of a yeast surface display system，summarzes the influence of major factors on the display system，the application of this technology in the degradation of cellulose. It provides guidance efficiency yeast surface display of cellulase and other multi-enzyme systems.