Optimization of nutrient feed concentration and addition time for production of poly(β-hydroxybutyrate)
PHB is an intracellular storage compound produced by many organisms under conditions of nutrient limitation (N, P, etc.) when carbon source is present in excess. Model-based fed-batch cultivation is one of the techniques to induce desired nutrient limitations intelligently for over production of suc...
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Published in | Enzyme and microbial technology Vol. 39; no. 5; pp. 1145 - 1151 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier Inc
04.09.2006
Elsevier Science |
Subjects | |
Online Access | Get full text |
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Summary: | PHB is an intracellular storage compound produced by many organisms under conditions of nutrient limitation (N, P, etc.) when carbon source is present in excess. Model-based fed-batch cultivation is one of the techniques to induce desired nutrient limitations intelligently for over production of such partially growth-associated polymeric products. In the present study, batch kinetics of PHB synthesis by
Wautersia eutropha was established in a bioreactor. Batch kinetics featured a biomass concentration of 19.68
g/l with a PHB content of 10.89
g/l in 60
h. A mathematical model was then developed, which adequately described the batch kinetics. The model equations were extrapolated to fed-batch cultivation by incorporating the dilution terms due to fresh nutrient (carbon and nitrogen) feeding. Model-based fed-batch fermentation was conducted by feeding nitrogen (7
g/l) from 20–30
h at the rate of 70
ml/h and fructose (300
g/l) from 24–34
h at the rate of 80
ml/h constantly which yielded 32
g/l biomass containing 14
g/l PHB in 50
h. The productivity was 1.5-times greater than that obtained in batch increasing from 0.18 to 0.28
g/l-h. The model proved to be highly instrumental in the design of suitable fed-batch cultivation. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0141-0229 1879-0909 |
DOI: | 10.1016/j.enzmictec.2006.02.023 |