title: Microbial production of palatinose through extracellular expression of a sucrose isomerase from Enterobacter sp. FMB-1 in Lactococcus lactis MG1363.
abstract: Sucrose isomerase (SIase) has been used to produce palatinose, a structural isomer of sucrose, which has many beneficial health properties, such as low-glycemic and low-insulinemic indices. A gene corresponding to SIase from Enterobacter sp. FMB-1 was expressed in Lactococcus lactis MG1363 using the P170 expression system. The autoinducible promoter (P170) and an optimized signal peptide (SP310mut2) were used to induce and secrete SIase in L. lactis. One-step Ni-NTA affinity chromatography and Western blot analysis demonstrated that SIase was successfully secreted to the culture supernatant, although 60% of the recombinant enzymes were retained inside the cells. The production of the recombinant SIase was highly correlated with pH (pH 6) and glucose concentration (30g/L) of the medium. The extracellularly produced recombinant SIase was functionally active, effectively transforming 50g/L sucrose to 36g/L palatinose, with a conversion rate of 72% in the culture supernatant.
authors.affiliation: Department of Food Science and Biotechnology, Graduate School of Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin, Republic of Korea.
authors.forename: Jong-Yul
authors.initials: JY
authors.lastname: Park
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Jung
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Seo
authors.forename: Suk-Jin
authors.initials: SJ
authors.lastname: Ha
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Yoon
authors.forename: Young-Cheul
authors.initials: YC
authors.lastname: Kim
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Shim
authors.forename: Cheon-Seok
authors.initials: CS
authors.lastname: Park
mesh_terms: D004754:Enterobacter / Q000502:physiology*; D045604:Extracellular Fluid / Q000201:enzymology; D024861:Genetic Enhancement / Q000379:methods*; D005964:Glucosyltransferases / Q000502:physiology*; D007534:Isomaltose / Q000031:analogs & derivatives* / Q000096:biosynthesis; D013294:Lactococcus lactis / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D007534:Isomaltose; D005964:Glucosyltransferases; C116853:sucrose isomerase; C008189:isomaltulose