Effects of exocellobiohydrolase CBHA on fermentation of tobacco leaves

In this paper, we used the glycosyl hydrolase CBHA as an exogenous additive to ferment tobacco. The CBHA was expressed with P. pastoris X-33 expression system. The P. pastoris expression system has many advantages, such as the target product can be secreted outside the cell, the endogenous secreted proteins are less than the bacterial expression system, and it is easy to purify. At the same time, compared with bacteria, it also has the advantages of fast growth rate, modification after scouring, and easy genetic manipulation. In addition, the linear DNA can be efficiently inserted into the chromosomes of yeast cells by cross-recombination, thus producing stable cell lines. The supernatant of yeast medium after induction was used to ferment low grade tobacco leaves planted in Guangxi, China. The effects of these exogenous additives on the bacterial community structure and function were studied by biochemical means and high throughput sequencing analysis.