title: Metabolic engineering of Ralstonia eutropha for the production of polyhydroxyalkanoates from sucrose.
abstract: A sucrose utilization pathway was established in Ralstonia eutropha NCIMB11599 and R. eutropha 437-540 by introducing the Mannheimia succiniciproducens MBEL55E sacC gene that encodes β-fructofuranosidase. These engineered strains were examined for the production of poly(3-hydroxybutyrate) [P(3HB)] and poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)], respectively, from sucrose as a carbon source. It was found that β-fructofuranosidase excreted into the culture medium could hydrolyze sucrose to glucose and fructose, which were efficiently used as carbon sources by recombinant R. eutropha strains. When R. eutropha NCIMB11599 expressing the sacC gene was cultured in nitrogen-free chemically defined medium containing 20 g/L of sucrose, a high P(3HB) content of 73.2 wt% could be obtained. In addition, R. eutropha 437-540 expressing the Pseudomonas sp. MBEL 6-19 phaC1437 gene and the Clostridium propionicum pct540 gene accumulated P(3HB-co-21.5 mol% LA) to a polymer content of 19.5 wt% from sucrose by the expression of the sacC gene and the Escherichia coli ldhA gene. The molecular weights of P(3HB) and P(3HB-co-21.5 mol%LA) synthesized in R. eutropha using sucrose as a carbon source were 3.52 × 10(5) (Mn ) and 2.19 × 10(4) (Mn ), respectively. The engineered R. eutropha strains reported here will be useful for the production of polyhydroxyalkanoates (PHAs) from sucrose, one of the most abundant and relatively inexpensive carbon sources.
authors.affiliation: Department of Environmental Engineering and Energy, Myongji University, Yongin, Gyeonggido, Republic of Korea.
authors.forename: Si Jae
authors.initials: SJ
authors.lastname: Park
authors.forename: Young-Ah
authors.initials: YA
authors.lastname: Jang
authors.forename: Won
authors.initials: W
authors.lastname: Noh
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Oh
authors.forename: Hyuk
authors.initials: H
authors.lastname: Lee
authors.forename: Yokimiko
authors.initials: Y
authors.lastname: David
authors.forename: Mary Grace
authors.initials: MG
authors.lastname: Baylon
authors.forename: Jihoon
authors.initials: J
authors.lastname: Shin
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Yang
authors.forename: So Young
authors.initials: SY
authors.lastname: Choi
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lee
mesh_terms: D061249:Batch Cell Culture Techniques; D020118:Cupriavidus necator / Q000235:genetics* / Q000378:metabolism*; D060847:Metabolic Engineering / Q000379:methods*; D054813:Polyhydroxyalkanoates / Q000032:analysis / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism*
chemical_list: D054813:Polyhydroxyalkanoates; D013395:Sucrose
keywords: Ralstonia eutropha; poly(3-hydroxybutyrate); poly(3-hydroxybutyrate-co-lactate); sucrose; β-fructofuranosidase