<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production"^^ . "Background: Although the production of poly-β-hydroxybutyrate (PHB) has many biological,\r\nenergetic and environmental advantages over chemically synthesized polymers, synthetic polymers\r\ncontinue to be produced industrially since the productivities of fermentation processes fr PHB are\r\nnot yet economically competitive. Improvement of a PHB fermentation requires good\r\nunderstanding and optimization under the realistic conditions of large bioreactors.\r\nLaboratory-scale studies have shown that co-cultures of Ralstonia eutropha and Lactobacillus\r\ndelbrueckii generate better fermentation efficiencies than R. eutropha alone. In large bioreactors,\r\nincomplete dispersioin and perturbations in the dissolved oxygen (DO) concentration, both of\r\nwhich affect the fermentation, have to be considered. This study analyzes the effect of DO\r\nfluctuations on bioreactor performance for both ideal and optimally dispersed broths.\r\nResults: Response coefficient analysis was employed to obtain quantitative information on the\r\neffect of DO perturbations on different variables. Three values of the Peclet number (Pe)\r\ncheracterized three levels of dispersion: Pe = 0.01 for nearly complete dispersion, Pe = 20 for\r\noptimum dispersion and Pe = 60 for insufficient dispersion. The response coefficients (RCs) of the\r\npairs of bacterial concentrations and the main substrates, glucose and ammonium chloride, showed\r\ncontrasting variations with time. Lactate, a critical intermediate, and PHB had similar RC profiles\r\nbut those of lactate were one to two orders of magnitude larger than other RCs. Significantly, the\r\noptimum Pe also resulted in the largest RCs, suggesting a balance between productivity and reactor\r\nstability.\r\nConclusion: Since R. eutropha requires oxygen for its growth whereas L. delbrueckii does not,\r\nfluctuations in the DO concentartion have a strong influence on the fermentation. Apart from this,\r\nthe mechanism of PHB biosynthesis indicates that control of lactate is a critical determinant of\r\nfermentation efficiency. The RC profiles indicate that, under non-ideal conditions, a compromise\r\nmay be required between PHB formation and reactor stability, especially in the latter half of the\r\nprocess."^^ . "2008" . . . "2" . "1" . . "Biomedcentral"^^ . . . "Journal of Biological Engineering"^^ . . . "17541611" . . . . . . . "Pratap R"^^ . "Patnaik"^^ . "Pratap R Patnaik"^^ . . . . . . "Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production (PDF)"^^ . . . . . . "patnaik2008.pdf"^^ . . . "Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production (Indexer Terms)"^^ . . . . . . "indexcodes.txt"^^ . . . "Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production (Image (PNG))"^^ . . . . . . "lightbox.jpg"^^ . . . "Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production (Image (PNG))"^^ . . . . . . "preview.jpg"^^ . . . "Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production (Image (PNG))"^^ . . . . . . "medium.jpg"^^ . . . "Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production (Image (PNG))"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #1069 \n\nResponse coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production\n\n" . "text/html" . . . "QD Chemistry"@en . .