title: Efficient aspartic acid production by a psychrophile-based simple biocatalyst.
abstract: We previously constructed a Psychrophile-based Simple bioCatalyst (PSCat) reaction system, in which psychrophilic metabolic enzymes are inactivated by heat treatment, and used it here to study the conversion of aspartic acid from fumaric acid mediated by the activity of aspartate ammonia-lyase (aspartase). In Escherichia coli, the biosynthesis of aspartic acid competes with that of L-malic acid produced from fumaric acid by fumarase. In this study, E. coli aspartase was expressed in psychrophilic Shewanella livingstonensis Ac10 heat treated at 50 °C for 15 min. The resultant PSCat could convert fumaric acid to aspartic acid without the formation of L-malic acid because of heat inactivation of psychrophilic fumarase activity. Furthermore, alginate-immobilized PSCat produced high yields of aspartic acid and could be re-used nine times. The results of our study suggest that PSCat can be applied in biotechnological production as a new approach to increase the yield of target compounds.
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, 739-8530, Japan. ttajima@hiroshima-u.ac.jp.|Core Research of Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan. ttajima@hiroshima-u.ac.jp.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Tajima
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, 739-8530, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Hamada
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, 739-8530, Japan.|Core Research of Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakashimada
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, 739-8530, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Kato
mesh_terms: D001220:Aspartate Ammonia-Lyase / Q000378:metabolism; D001224:Aspartic Acid / Q000096:biosynthesis*; D055162:Biocatalysis; D001709:Biotechnology / Q000379:methods; D004795:Enzyme Stability; D017743:Equipment Reuse; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism; D005649:Fumarate Hydratase / Q000378:metabolism; D005650:Fumarates / Q000378:metabolism; D006358:Hot Temperature; D008293:Malates / Q000378:metabolism; D020592:Shewanella / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
chemical_list: D005650:Fumarates; D008293:Malates; D001224:Aspartic Acid; C030298:malic acid; C032005:fumaric acid; D005649:Fumarate Hydratase; D001220:Aspartate Ammonia-Lyase
keywords: Alginate; Aspartic acid; Biomass; Immobilization; Psychrophilic bacteria