Display of Bacillus macerans cyclodextrin glucanotransferase on cell surface of Saccharomyces cerevisiae

Bacillus macerans cyclodextrin glucanotransferase (CGTase) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein, Aga1p. The surface display of CGTase was confirmed by immunofluorescence microscopy and its enzymatic ability to form alpha-cyclodextrin from starch. The maximum surface-display of CGTase was obtained by growing recombinant S. cerevisiae at 20degreesC and pH 6.0. S. cerevisiae cells displaying CGTase on their surface consumed glucose and maltose, inhibitory byproducts of the CGTase reaction, to enhance the purity of produced cyclodextrins. Accordingly, the experimental results described herein suggest a possibility of using the recombinant S. cerevisiae anchored with bacterial CGTase on the cell surface as a whole-cell biocatalyst for the production of cyclodextrin.