title: Evaluation of by-products from the biodiesel industry as fermentation feedstock for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production by Cupriavidus necator.
abstract: Utilization of by-products from oilseed-based biodiesel production (crude glycerol, rapeseed meal hydrolysates) for microbial polyhydroxyalkanoate (PHA) production could lead to the replacement of expensive carbon sources, nutrient supplements and precursors for co-polymer production. Batch fermentations in shake flasks with varying amounts of free amino nitrogen led to the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV)) with a 2.8-8% 3HV content. Fed-batch fermentations in shake flasks led to the production of 10.9g/L P(3HB-co-3HV) and a 55.6% P(3HB-co-3HV) content. NaCl concentrations between 2 and 6g/L gradually became inhibitory to bacterial growth and PHA formation, whereas in the case of K(2)SO(4), the inhibitory effect was observed only at concentrations higher than 20g/L. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and nuclear magnetic resonance ((13)C NMR) demonstrated that the incorporation of 3HV into the obtained P(3HB-co-3HV) lowered glass transition temperature, crystallinity and melting point as compared to polyhydroxybutyrate. Integrating PHA production in existing oilseed-based biodiesel plants could enhance the viability and sustainability of this first generation biorefinery.
authors.affiliation: Department of Physical Chemistry and Applied Thermodynamics, Escuela Politecnica Superior, University of Cordoba, campus de excelencia agroalimentario, ceiA3, 23071 Cordoba, Spain.
authors.forename: I L
authors.initials: IL
authors.lastname: García
authors.forename: J A
authors.initials: JA
authors.lastname: López
authors.forename: M P
authors.initials: MP
authors.lastname: Dorado
authors.forename: N
authors.initials: N
authors.lastname: Kopsahelis
authors.forename: M
authors.initials: M
authors.lastname: Alexandri
authors.forename: S
authors.initials: S
authors.lastname: Papanikolaou
authors.forename: M A
authors.initials: MA
authors.lastname: Villar
authors.forename: A A
authors.initials: AA
authors.lastname: Koutinas
mesh_terms: D056804:Biofuels; D029741:Brassica rapa; D020118:Cupriavidus necator / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D005990:Glycerol; D007220:Industrial Waste; D011091:Polyesters / Q000737:chemistry / Q000378:metabolism*; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis*; D000094122:Polyhydroxybutyrates
chemical_list: D056804:Biofuels; D005990:Glycerol; D007220:Industrial Waste; D011091:Polyesters; D054813:Polyhydroxyalkanoates; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates