title: Effect of cultivation parameters on the production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and poly(3-hydroxybutyrate-4-hydroxybutyrate-3-hydroxyvalerate) by Cupriavidus necator using waste glycerol.
abstract: Short-chain polyhydroxyalkanoate co-polymers (poly(3-hydroxybutyrate-co-4-hydroxybutyrate)) (P(3HB-co-4HB)) and terpolymers (poly(3-hydroxybutyrate-4-hydroxybutyrate-3-hydroxyvalerate)) (P(3HB-4HB-3HV)) were produced using high-cell density fed-batch cultures of Cupriavidus necator DSM 545. C-source for growth and 3HB synthesis was waste glycerol (GRP) from a biodiesel plant. Incorporation of 4HB monomers was promoted by γ-butyrolactone (GBL). Propionic acid (PA), a stimulator of 4HB accumulation, increased the 4HB molar ratio 2-fold, but also acted as 3HV precursor, yielding P(3HB-4HB-3HV). Dissolved oxygen (DOC) was a key parameter for % PHA accumulation and volumetric productivity (Prod(vol)). 4HB molar ratio increased in the presence of PA and with extended accumulation time. By manipulating DOC and cultivation time, P(3HB-4HB) with between 11.4 and 21.5 molar% of 4HB were attained. Similarly, P(3HB-4HB-3HV) was obtained with 4HB molar% between 24.8% and 43.6% and 3HV% from 5.6% to 9.8%. Mw varied between 5.5 × 10(5) and 1.37 × 10(6)Da. PHA production from GRP helps reducing production costs with concomitant GRP valorization.
authors.affiliation: ICTPOL - Instituto de Ciência e Tecnologia de Polímeros, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
authors.forename: João M B T
authors.initials: JM
authors.lastname: Cavalheiro
authors.forename: Rodrigo S
authors.initials: RS
authors.lastname: Raposo
authors.forename: M Catarina M D
authors.initials: MC
authors.lastname: de Almeida
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Cesário
authors.forename: Chantal
authors.initials: C
authors.lastname: Sevrin
authors.forename: Christian
authors.initials: C
authors.lastname: Grandfils
authors.forename: M M R
authors.initials: MM
authors.lastname: da Fonseca
mesh_terms: D020118:Cupriavidus necator / Q000378:metabolism*; D005612:Freeze Drying; D005990:Glycerol / Q000737:chemistry*; D006885:Hydroxybutyrates / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D011091:Polyesters / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D005990:Glycerol; D006885:Hydroxybutyrates; D011091:Polyesters; C510062:poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate); D000094122:Polyhydroxybutyrates; C068056:poly(3-hydroxybutyrate-co-4-hydroxybutyrate)