title: Type II thioesterase improves heterologous biosynthesis of valinomycin in Escherichia coli.
abstract: Heterologous expression of secondary metabolite biosynthesis pathways in a surrogate host, e.g. Escherichia coli, has emerged in recent years as an effective way to produce complex natural products. The nonribosomal peptide (NRP) antibiotic valinomycin has been recombinantly produced in E. coli through reconstitution of its biosynthetic pathway from the native producer Streptomyces tsusimaensis. In this study, a discrete protein type II thioesterase (TEII) encoded in the valinomycin gene cluster was coexpressed in the valinomycin producing E. coli strain. Valinomycin titers were significantly improved from 0.5 (without TEII coexpression) to 3.3 mg L(-1), which demonstrates the reconstitutive function of TEII involved in NRP biosynthesis. Based on a flask scale fed-batch cultivation system, repeated feeding of the glucose polymer during the cultivation further increased cell density and valinomycin titer up to 55 (OD600) and 13 mg L(-1), respectively. This indicates scalable high cell density cultivation in a bioreactor for overproduction of valinomycin will be a potential and feasible approach. In this work we present an in vivo example to show that TEII plays a positive role in heterologous valinomycin production.
authors.affiliation: Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstraße 76, ACK24, D-13355 Berlin, Germany. Electronic address: ljtboa@gmail.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.affiliation: Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstraße 76, ACK24, D-13355 Berlin, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Jaitzig
authors.affiliation: Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstraße 76, ACK24, D-13355 Berlin, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Theuer
authors.affiliation: Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstraße 76, ACK24, D-13355 Berlin, Germany.
authors.forename: Ongey Elvis
authors.initials: OE
authors.lastname: Legala
authors.affiliation: Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, D-10623 Berlin, Germany.
authors.forename: Roderich D
authors.initials: RD
authors.lastname: Süssmuth
authors.affiliation: Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstraße 76, ACK24, D-13355 Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Neubauer
mesh_terms: D019149:Bioreactors; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D013302:Streptomyces / Q000235:genetics; D013869:Thiolester Hydrolases / Q000235:genetics / Q000378:metabolism*; D014634:Valinomycin / Q000032:analysis / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D014634:Valinomycin; D064429:Fatty Acid Synthases; D013869:Thiolester Hydrolases; C022738:thioesterase II
keywords: EnBase; Escherichia coli; Heterologous biosynthesis; Type II thioesterase; Valinomycin