원문정보
초록
영어
Nowadays, many enzymes are engineered by using directed evolution for application in the industrial processes. There exists a functional gap between natural conditions for the activity of enzymes and industrial conditions that we require for using enzymes under industry. Among
them, xylanase A is one of the important enzymes which catalyzes the hydrolysis of xylan, a major constituent of hemicelluloses. The goal of this research is to improve alkaline pH stability of xylanase A from Bacillus subtilis 168, which has optimum activity in pH 5, using directed
evolution. At first, strain and expression vector for this research, which can produce xylanase A, were selected to make mutant libraries. Congo red dying method was used in order to check the expression and the secretion of xylanase A from a variety of hosts. E. coli w3110 and Pucp19A were selected for this study. Then, error-prone PCR was used to make mutant libraries easily. Congo red method was also used to screen the mutant which has xylanase A with the improved alkaline pH stability.