title: Polyhydroxyalkanoates production with Ralstonia eutropha from low quality waste animal fats.
abstract: Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polyesters considered as alternatives to petroleum-based plastics. Ralstonia eutropha is a model organism for PHA production. Utilizing industrially rendered waste animal fats as inexpensive carbon feedstocks for PHA production is demonstrated here. An emulsification strategy, without any mechanical or chemical pre-treatment, was developed to increase the bioavailability of solid, poorly-consumable fats. Wild type R. eutropha strain H16 produced 79-82% (w/w) polyhydroxybutyrate (PHB) per cell dry weight (CDW) when cultivated on various fats. A productivity of 0.3g PHB/(L × h) with a total PHB production of 24 g/L was achieved using tallow as carbon source. Using a recombinant strain of R. eutropha that produces poly(hydroxybutyrate-co-hydroxyhexanoate) [P(HB-co-HHx)], 49-72% (w/w) of PHA per CDW with a HHx content of 16-27 mol% were produced in shaking flask experiments. The recombinant strain was grown on waste animal fat of the lowest quality available at lab fermenter scale, resulting in 45 g/L CDW with 60% (w/w) PHA per CDW and a productivity of 0.4 g PHA/(L × h). The final HHx content of the polymer was 19 mol%. The use of low quality waste animal fats as an inexpensive carbon feedstock exhibits a high potential to accelerate the commercialization of PHAs.
authors.affiliation: Department of Applied and Molecular Microbiology, Technische Universität Berlin, Germany; Fraunhofer Institute for Production Systems and Design Technology IPK, Berlin, Germany. Electronic address: sebastian.riedel@ipk.fraunhofer.de.
authors.forename: Sebastian L
authors.initials: SL
authors.lastname: Riedel
authors.affiliation: Department of Applied and Molecular Microbiology, Technische Universität Berlin, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Jahns
authors.affiliation: Department of Applied and Molecular Microbiology, Technische Universität Berlin, Germany.
authors.forename: Steven
authors.initials: S
authors.lastname: Koenig
authors.affiliation: Department of Applied and Molecular Microbiology, Technische Universität Berlin, Germany.
authors.forename: Martina C E
authors.initials: MC
authors.lastname: Bock
authors.affiliation: Department of Bioengineering, University of Massachusetts Dartmouth, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Brigham
authors.affiliation: Department of Biotechnology, Beuth University of Applied Sciences, Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Bader
authors.affiliation: Department of Applied and Molecular Microbiology, Technische Universität Berlin, Germany; Research Institute for Microbiology, Versuchs-und Lehranstalt für Brauerei Berlin e.V., Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Stahl
mesh_terms: D000818:Animals; D002417:Cattle; D020118:Cupriavidus necator / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism*; D007218:Industrial Microbiology / Q000379:methods*; D007220:Industrial Waste; D010938:Plant Oils / Q000378:metabolism*; D054813:Polyhydroxyalkanoates / Q000378:metabolism*; D011200:Poultry; D013552:Swine
chemical_list: D004041:Dietary Fats; D007220:Industrial Waste; D010938:Plant Oils; D054813:Polyhydroxyalkanoates
keywords: PHA production; Polyhydroxyalkanoate; Ralstonia eutropha; Waste animal fats; Waste lipids; Waste plant oils