title: High cell density cultivation of Pseudomonas putida KT2440 using glucose without the need for oxygen enriched air supply.
abstract: High Cell Density (HCD) cultivation of bacteria is essential for the majority of industrial processes to achieve high volumetric productivity (g L(-1) h(-1) ) of a bioproduct of interest. This study developed a fed batch bioprocess using glucose as sole carbon and energy source for the HCD of the well described biocatalyst Pseudomonas putida KT2440 without the supply of oxygen enriched air. Growth kinetics data from batch fermentations were used for building a bioprocess model and designing feeding strategies. An exponential followed by linearly increasing feeding strategy of glucose was found to be effective in maintaining biomass productivity while also delaying the onset of dissolved oxygen (supplied via compressed air) limitation. A final cell dry weight (CDW) of 102 g L(-1) was achieved in 33 h with a biomass productivity of 3.1 g L(-1) h(-1) which are the highest ever reported values for P. putida strains using glucose without the supply of pure oxygen or oxygen enriched air. The usefulness of the biomass as a biocatalyst was demonstrated through the production of the biodegradable polymer polyhydroxyalkanoate (PHA). When nonanoic acid (NA) was supplied to the glucose grown cells of P. putida KT2440, it accumulated 32% of CDW as PHA in 11 h (2.85 g L(-1) h(-1) ) resulting in a total of 0.56 kg of PHA in 18 L with a yield of 0.56 g PHA g NA(-1) .
authors.affiliation: School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland; Technology Centre for Biorefining and Bioenergy, National University of Ireland, Galway, Ireland.
authors.forename: Reeta
authors.initials: R
authors.lastname: Davis
authors.forename: Gearoid
authors.initials: G
authors.lastname: Duane
authors.forename: Shane T
authors.initials: ST
authors.lastname: Kenny
authors.forename: Federico
authors.initials: F
authors.lastname: Cerrone
authors.forename: Maciej W
authors.initials: MW
authors.lastname: Guzik
authors.forename: Ramesh P
authors.initials: RP
authors.lastname: Babu
authors.forename: Eoin
authors.initials: E
authors.lastname: Casey
authors.forename: Kevin E
authors.initials: KE
authors.lastname: O'Connor
mesh_terms: D061249:Batch Cell Culture Techniques; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D004734:Energy Metabolism; D005227:Fatty Acids / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D054813:Polyhydroxyalkanoates / Q000378:metabolism; D016958:Pseudomonas putida / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D054813:Polyhydroxyalkanoates; D002244:Carbon; C008776:pelargonic acid; D005947:Glucose; D010100:Oxygen
keywords: Pseudomonas putida KT2440; bioprocess engineering; fed-batch; glucose; modeling; polyhydroxyalkanoates