title: Poly(3-hydroxybutyrate) production by Halomonas boliviensis in fed-batch culture.
abstract: High poly(3-hydroxybutyrate) (PHB) content and volumetric productivity were achieved by fed-batch culture of Halomonas boliviensis using a defined medium. Initial shake flask cultivations in a minimal medium revealed that the growth of H. boliviensis was supported only when the medium was supplemented with aspartic acid, glycine, or glutamine. Addition of 0.1% (w/v) glutamine in the medium resulted in the highest cell dry weight (CDW; 3.9 g l(-1)). Glutamine was replaced by the less expensive monosodium glutamate (MSG) in the medium without any notable change in the final cell density. Effect of initial concentrations of NH(4)Cl and K(2)HPO(4) on cell growth and PHB accumulation by H. boliviensis was then analyzed using a fed-batch fermentation system. The best conditions for PHB production by H. boliviensis were attained using 0.4% (w/v) NH(4)Cl and 0.22% (w/v) K(2)HPO(4) and adding MSG intermittently to the fermentor. Poly(3-hydroxybutyrate) content and CDW reached 90 wt.% and 23 g l(-1), respectively, after 18 h of cultivation. In order to increase CDW and PHB content, MSG, NH(4)Cl, and K(2)HPO(4) were initially fed to the fermentor to maintain their concentrations at 2%, 0.4%, and 0.22% (w/v), respectively, and subsequently their feed was suppressed. This resulted in a CDW of 44 g l(-1), PHB content of 81 wt.%, and PHB volumetric productivity of 1.1 g l(-1) h(-1).
authors: Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden. Jorge.Quillaguaman@biotek.lu.se
authors: Jorge
authors: J
authors: Quillaguamán
authors: Thuoc
authors: T
authors: Doan-Van
authors: Héctor
authors: H
authors: Guzmán
authors: Daniel
authors: D
authors: Guzmán
authors: Javier
authors: J
authors: Martín
authors: Akaraonye
authors: A
authors: Everest
authors: Rajni
authors: R
authors: Hatti-Kaul
mesh_terms: D000643:Ammonium Chloride; D001224:Aspartic Acid / Q000378:metabolism; D018533:Biomass; D003470:Culture Media / Q000737:chemistry; D005947:Glucose / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D020632:Halomonas / Q000254:growth & development / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D011091:Polyesters / Q000378:metabolism*; D017680:Potassium Compounds / Q000378:metabolism; D012970:Sodium Glutamate / Q000378:metabolism; D013997:Time Factors; D000094122:Polyhydroxybutyrates
chemical_list: D000643:Ammonium Chloride; D001224:Aspartic Acid; D003470:Culture Media; D005947:Glucose; D005973:Glutamine; D005998:Glycine; D006885:Hydroxybutyrates; D010710:Phosphates; D011091:Polyesters; D017680:Potassium Compounds; D012970:Sodium Glutamate; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates; C013216:potassium phosphate