title: Improved bread-baking process using Saccharomyces cerevisiae displayed with engineered cyclodextrin glucanotransferase.
abstract: A bread-baking process was developed using a potential novel enzyme, cyclodextrin glucanotransferase[3-18] (CGTase[3-18]), that had previously been engineered to have enhanced hydrolyzing activity with little cyclodextrin (CD) formation activity toward starch. CGTase[3-18] was primarily manipulated to be displayed on the cell surface of Saccharomyces cerevisiae. S. cerevisiae carrying pdeltaCGT integrated into the chromosome exhibited starch-hydrolyzing activity at the same optimal pH and temperature as the free enzyme. Volumes of the bread loaves and rice cakes prepared using S. cerevisiae/pdeltaCGT increased by 20% and 45%, respectively, with no detectable CD. Retrogradation rates of the bread and rice cakes decreased significantly during storage. In comparison to the wild type, S. cerevisiae/pdeltaCGT showed improved viability during four freeze-thaw cycles. The results indicated that CGTase[3-18] displayed on the surface of yeast hydrolyzed starch to glucose and maltose that can be used more efficiently for yeast fermentation. Therefore, display of an antistaling enzyme on the cell surface of yeast has potential for enhancing the baking process.
authors.affiliation: Center for Agricultural Biomaterials, School of Agricultural Biotechnology, Seoul National University, Shillim-dong, Kwanak-gu, Seoul 151-742, Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Shim
authors.forename: Nam-Seok
authors.initials: NS
authors.lastname: Seo
authors.forename: Sun-Ah
authors.initials: SA
authors.lastname: Roh
authors.forename: Jung-Wan
authors.initials: JW
authors.lastname: Kim
authors.forename: Hyunju
authors.initials: H
authors.lastname: Cha
authors.forename: Kwan-Hwa
authors.initials: KH
authors.lastname: Park
mesh_terms: D001939:Bread; D002462:Cell Membrane / Q000201:enzymology; D003001:Cloning, Molecular; D003296:Cooking; D004795:Enzyme Stability; D018014:Gene Transfer Techniques; D005818:Genetic Engineering; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D012275:Oryza; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000378:metabolism; D015003:Yeasts / Q000235:genetics*
chemical_list: D011994:Recombinant Proteins; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase