Effect of fluid dynamic conditions on 2,3-butanediol production by Raoultella terrigena in SBTR: oxygen transfer and uptake rates
| Autor: | Felix Garcia-Ochoa, Alberto Rodríguez, Vanessa Ripoll, Emilio Miraflores Gómez, Victoria E. Santos |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine General Chemical Engineering chemistry.chemical_element Bacterial growth 01 natural sciences Oxygen Inorganic Chemistry 03 medical and health sciences chemistry.chemical_compound Viscosity 010608 biotechnology 2 3-Butanediol Shear stress Food science Waste Management and Disposal Chromatography Renewable Energy Sustainability and the Environment Chemistry Organic Chemistry Raoultella terrigena Pollution 030104 developmental biology Fuel Technology Fermentation Flux (metabolism) Biotechnology |
| Zdroj: | Journal of Chemical Technology & Biotechnology. 92:1266-1275 |
| ISSN: | 0268-2575 |
| Popis: | BACKGROUND The fluid dynamic conditions play a key role in the development and scaling-up of bioprocesses. In aerobic cultures, oxygen is an essential substrate for microbial growth, production and culture maintenance; an effective gas–liquid transfer must be achieved. Changes in fluid dynamics due to stirrer speed can affect the culture negatively, causing hydrodynamic stress (increasing shear stress) or oxidative stress (by an increase of available oxygen in the liquid phase). RESULTS Under oxygen-limiting conditions, specific growth rate increases with stirrer speed, and several fermentation products were specifically released to the culture medium. BD production increased with stirrer speed, reaching a maximum at 400 rpm. When the agitation was increased over 550 rpm, the metabolic flux was mainly routed to increase the cell growth. Negative effects of fluid dynamic conditions on biomass production were observed at 1900 and 2000 rpm. Cellular response to shear stress conditions was also shown in the large increase with time of the broth viscosity. CONCLUSIONS R. terrigena is able to adapt the carbon metabolic flux to the availability of oxygen, producing fermentation products, alcohols or directing microbial growth. Moreover, cells can withstand aggressive agitation conditions (until 1600 rpm). |
| Databáze: | OpenAIRE |
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