Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK

Filters
Reset filters

Settings
Now showing 1 - 4 of 4
  • Publication
    Polyhydroxyalkanoates production with Ralstonia eutropha from low quality waste animal fats
    ( 2015)
    Riedel, S.L.
    ;
    Jahns, S.
    ;
    Koenig, S.
    ;
    Bock, M.C.E.
    ;
    Brigham, C.J.
    ;
    Bader, J.
    ;
    Stahl, U.
    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 0.3 g 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.
  • Publication
    Lipid and fatty acid metabolism in Ralstonia eutropha: Relevance for the biotechnological production of value-added products
    ( 2014)
    Riedel, S.L.
    ;
    Lu, J.N.
    ;
    Stahl, U.
    ;
    Brigham, C.J.
    Lipid and fatty acid metabolism has been well studied in model microbial organisms like Escherichia coli and Bacillus subtilis. The major precursor of fatty acid biosynthesis is also the major product of fatty acid degradation (beta-oxidation), acetyl-CoA, which is a key metabolite for all organisms. Controlling carbon flux to fatty acid biosynthesis and from beta-oxidation allows for the biosynthesis of natural products of biotechnological importance. Ralstonia eutropha can utilize acetyl-CoA from fatty acid metabolism to produce intracellular polyhydroxyalkanoate (PHA). R. eutropha can also be engineered to utilize fatty acid metabolism intermediates to produce different PHA precursors. Metabolism of lipids and fatty acids can be rerouted to convert carbon into other value-added compounds like biofuels. This review discusses the lipid and fatty acid metabolic pathways in R. eutropha and how they can be used to construct reagents for the biosynthesis of products of industrial importance. Specifically, how the use of lipids or fatty acids as the sole carbon source in R. eutropha cultures adds value to these biotechnological products will be discussed here.
  • Publication
    Trends in der Industriellen Teilereinigung - Welches Potenzial hat Kohlendioxid?
    ( 2009)
    Krieg, M.C.
    ;
    Bilz, M.
    ;
    Mankiewicz, J.
    Das auf dem europäischen Markt angebotene technische CO2 wird nur zu einem geringen Teil aus natürlichen Quellen gewonnen, der Großteil fällt als Abfallprodukt aus Gärprozessen und in der chemischen Industrie an. Seine Nutzung ist vollkommen treibhausneutral, vielmehr können durch den Einsatz von Kohlendioxid zum Teil stark umweltgefährdende Stoffe wie halogenierte Kohlenwasserstoffe beinhaltende Kälte- oder Lösemittel mit einem erheblich größeren Treibhauspotenzial ersetzt werden. Auf Grund seiner verfahrenstechnischen Vorteile, wie trocken, rückstandsfrei, substratschondend und umweltneutral, hat sich das Strahlen mit festem Kohlendioxid in den letzten Jahren in unterschiedlichen Anwendungsfeldern etabliert. Die Möglichkeiten sind derzeit längst nicht ausgeschöpft. Gängige Verfahren und sich abzeichnende Entwicklungen werden dargestellt.
  • Publication
    Kalt gestellt
    ( 2007)
    Uhlmann, E.
    ;
    Stahl, U.
    ;
    Hollan, R.
    ;
    Kristan, G.