title: Fed-batch strategies using butyrate for high cell density cultivation of Pseudomonas putida and its use as a biocatalyst.
abstract: A mathematically based fed-batch bioprocess demonstrated the suitability of using a relatively cheap and renewable substrate (butyric acid) for Pseudomonas putida CA-3 high cell density cultivation. Butyric acid fine-tuned addition is critical to extend the fermentation run and avoid oxygen consumption while maximising the biomass volumetric productivity. A conservative submaximal growth rate (μ of 0.25 h(-1)) achieved 71.3 g L(-1) of biomass after 42 h of fed-batch growth. When a more ambitious feed rate was supplied in order to match a μ of 0.35 h(-1), the volumetric productivity was increased to 2.0 g L(-1) h(-1), corresponding to a run of 25 h and 50 g L(-1) of biomass. Both results represent the highest biomass and the best biomass volumetric productivity with butyrate as a sole carbon source. However, medium chain length polyhydroxyalkanoate (mcl-PHA) accumulation with butyrate grown cells is low (4 %). To achieve a higher mcl-PHA volumetric productivity, decanoate was supplied to butyrate grown cells. This strategy resulted in a PHA volumetric productivity of 4.57 g L(-1) h(-1) in the PHA production phase and 1.63 g L(-1) h(-1)over the lifetime of the fermentation, with a maximum mcl-PHA accumulation of 65 % of the cell dry weight.
authors.affiliation: School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Federico
authors.initials: F
authors.lastname: Cerrone
authors.forename: Gearoid
authors.initials: G
authors.lastname: Duane
authors.forename: Eoin
authors.initials: E
authors.lastname: Casey
authors.forename: Reeta
authors.initials: R
authors.lastname: Davis
authors.forename: Ian
authors.initials: I
authors.lastname: Belton
authors.forename: Shane T
authors.initials: ST
authors.lastname: Kenny
authors.forename: Maciej W
authors.initials: MW
authors.lastname: Guzik
authors.forename: Trevor
authors.initials: T
authors.lastname: Woods
authors.forename: Ramesh P
authors.initials: RP
authors.lastname: Babu
authors.forename: Kevin
authors.initials: K
authors.lastname: O'Connor
mesh_terms: D061249:Batch Cell Culture Techniques; D018533:Biomass; D001711:Biotransformation; D002087:Butyrates / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D003651:Decanoates / Q000378:metabolism; D004798:Enzymes; D008962:Models, Theoretical; D054813:Polyhydroxyalkanoates / Q000378:metabolism; D016958:Pseudomonas putida / Q000201:enzymology* / Q000254:growth & development*
chemical_list: D002087:Butyrates; D003651:Decanoates; D004798:Enzymes; D054813:Polyhydroxyalkanoates; D002244:Carbon