Enhancing the stability of xylanase from Cellulomonas fimi by cell-surface display on Escherichia coli.
OBJECTIVE
The cell-surface display of Cex, which encodes xylanase and exoglucanase from Cellulomonas fimi, was constructed on Escherichia coli using PgsA as the anchor protein. Characterization of the cell-surface display of Cex was performed.


RESULTS
PgsA was fused to the N-terminus of Cex and six histidines were utilized as spacers between the targeting and anchor proteins. Successful cell-surface display of Cex was demonstrated by Western blot and immunofluorescence analyses on E. coli C41 (DE3). According to the time-course analysis, the xylanase activity of Cex was achieved at 49Ug(-1) dry cell weight after 12 h culture at 37°C. The optimal temperature and pH ranges of the cell-surface displayed protein with whole-cell were broader than the corresponding ranges of the purified form. Further determination of thermostability indicated that the half-life of cell-surface displayed Cex was 1·6 times longer than that of purified Cex at 60°C.


CONCLUSIONS
We have successfully developed the cell-surface display of xylanase on E. coli. The cell-surface display can enhance the stability of xylanase against changes in temperature and has the potential of becoming a whole-cell biocatalyst for industrial applications, such as biobleaching of paper and production of renewable energy.


CONCLUSIONS
The results demonstrated that the cell-surface display of xylanase embedded in the cell membrane is more stable than that of the purified enzyme. Thus, to improve the stability of heterologous proteins production, cell-surface display using the PgsA anchor protein as a tool can be considered in E. coli.
Department of Biological Science and Technology, National Chiao Tung University, HsinChu, Taiwan.
Y-P
YP
Chen
I-E
IE
Hwang
C-J
CJ
Lin
H-J
HJ
Wang
C-P
CP
Tseng
D002462:Cell Membrane / Q000201:enzymology*; D040143:Cellulomonas / Q000201:enzymology*; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000378:metabolism*; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D013696:Temperature
D011993:Recombinant Fusion Proteins; D043364:Endo-1,4-beta Xylanases