Influence of oxygen transfer on Pseudomonas putida effects on growth rate and biodesulfurization capacity

Escobar, Sebastián; Rodrı́guez, A.; Gómez, Eduardo Escalante; Alcón, Almudena; Santos, Victoria E.; Garcı́a-Ochoa, Félix

doi:10.1007/s00449-016-1536-6

Cited by 21 publications

(36 citation statements)

References 31 publications

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“…Microbial growth rate has been described according to Equation (3), employed in previous work for different bioprocesses:

\frac{d C_{X}}{d t} = μ_{max} C_{X} ((), 1 - \frac{C_{X}}{C_{X}^{italicmax}})

If this equation is integrated with the boundary condition ( t = 0 ; C X = C X 0 ), the logistic growth equation is obtained:

C_{X} ((), t) = \frac{C_{X_{0}} e x p ((), μ_{max} t)}{1 - \frac{C_{X_{0}}}{C_{X}^{italicmax}} ([], 1 - e x p ((), μ_{max} t))}

…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…The oxygen mass balance in the liquid phase, assuming well‐mixed culture, can be established by:

\frac{d C_{O_{2}}}{d t} = O T R - italicOUR

OTR depends on the mass coefficient transfer, k L , the specific interfacial area, a , and the driving force of the oxygen transfer, which is the difference between the equilibrium dissolved oxygen concentration in the liquid phase at working pressure and temperature,

C_{O_{2}}^{*}

, and the DO concentration in the broth,

C_{O_{2}}

, according to:

O T R = k_{L} a \cdot ((), C_{O_{2}}^{*} - C_{O_{2}})

OTR can be determined by an oxygen mass balance in the gas phase by the difference between the inlet and outlet oxygen molar flow rates ( F O2 IN and F O2 OUT , respectively), as follows:

\frac{F_{O_{2}}^{IN} - F_{O_{2}}^{OUT}}{V} = O T R

Once OTR is determined and DO concentration is measured in the liquid phase, k L a can be calculated directly from Equations (6) and (7), yielding:

k_{L} a = \frac{F_{O_{2}}^{IN} - F_{O_{2}}^{OUT}}{V \cdot ((), C_{O_{2}}^{*} - C_{O_{2}})}

Then OUR can be calculated according to Equation (5), once OTR and DO oxygen profile are known, calculating dC O2 /dt by numerical methods, such as those described elsewhere …”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…In stirred tank bioreactors (STBR), if stirrer speed is increased, the mass transfer coefficient also increases and the fluid dynamics can affect the culture, provoking hydrodynamic stress (by increasing the shear stress) or oxidative stress (by increasing DO concentration). This may affect the growth rate, but also the production rate of the different metabolites, or both …”

Section: Introductionmentioning

confidence: 99%

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Effect of fluid dynamic conditions on 2,3‐butanediol production by Raoultella terrigena in SBTR: oxygen transfer and uptake rates

Rodríguez

Ripoll

Santos

et al. 2016

J of Chemical Tech & Biotech

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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. 2,3‐butanediol 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 of the broth viscosity over time. CONCLUSIONS Raoultella 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 (up to 1600 rpm). © 2016 Society of Chemical Industry

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“…Microbial growth rate has been described according to Equation (3), employed in previous work for different bioprocesses:

\frac{d C_{X}}{d t} = μ_{max} C_{X} ((), 1 - \frac{C_{X}}{C_{X}^{italicmax}})

If this equation is integrated with the boundary condition ( t = 0 ; C X = C X 0 ), the logistic growth equation is obtained:

C_{X} ((), t) = \frac{C_{X_{0}} e x p ((), μ_{max} t)}{1 - \frac{C_{X_{0}}}{C_{X}^{italicmax}} ([], 1 - e x p ((), μ_{max} t))}

…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…The oxygen mass balance in the liquid phase, assuming well‐mixed culture, can be established by:

\frac{d C_{O_{2}}}{d t} = O T R - italicOUR

C_{O_{2}}^{*}

, and the DO concentration in the broth,

C_{O_{2}}

, according to:

O T R = k_{L} a \cdot ((), C_{O_{2}}^{*} - C_{O_{2}})

OTR can be determined by an oxygen mass balance in the gas phase by the difference between the inlet and outlet oxygen molar flow rates ( F O2 IN and F O2 OUT , respectively), as follows:

\frac{F_{O_{2}}^{IN} - F_{O_{2}}^{OUT}}{V} = O T R

Once OTR is determined and DO concentration is measured in the liquid phase, k L a can be calculated directly from Equations (6) and (7), yielding:

k_{L} a = \frac{F_{O_{2}}^{IN} - F_{O_{2}}^{OUT}}{V \cdot ((), C_{O_{2}}^{*} - C_{O_{2}})}

Then OUR can be calculated according to Equation (5), once OTR and DO oxygen profile are known, calculating dC O2 /dt by numerical methods, such as those described elsewhere …”

Section: Theoretical Backgroundmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of fluid dynamic conditions on 2,3‐butanediol production by Raoultella terrigena in SBTR: oxygen transfer and uptake rates

Rodríguez

Ripoll

Santos

et al. 2016

J of Chemical Tech & Biotech

Self Cite

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“…Firstly, the optimal cell age was established and the enhancing of the process by addition of co‐substrates was evaluated . Subsequently, a kinetic model was proposed in order to describe the experimental results and the influence of OTR over the biomass growth and the desulfurization capacity was studied, by changing the agitation or the airflow rate …”

Section: Introductionmentioning

confidence: 99%

“…The results showed that, if the culture is carried out at a high agitation, which induces high dissolved oxygen concentration, the growth rate increases and the cells are not affected by shear stress. However, the desulfurization capacity operating with resting cells present a dramatic decrease when the cells are exposed to a stirrer speed higher than 300 rpm …”

Section: Introductionmentioning

confidence: 99%

Behavior of several pseudomonas putida strains growth under different agitation and oxygen supply conditions

Rodríguez

Escobar

Gómez

et al. 2018

Biotechnology Progress

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The growth rate of four strains of Pseudomonas putida, KT2440, KT2442, KTH2, and KTH2 (pESOX3), under different fluid dynamic conditions has been studied. The cultures were conducted in a stirred tank bioreactor by changing the stirrer speed. Several process variables, such as biomass concentration, dissolved oxygen concentration, oxygen mass transfer rate and oxygen uptake rate, have been measured or calculated. Also cell viability was determined by viable colony counting in Petri dishes and culture samples were subjected into a transmission electron microscopy analysis, in order to describe the integrity of the individual cells. The experimental results show that the genetically modified organisms, the strains KTH2 and KTH2 (pESOX3), present a different growth under low agitation conditions, and low oxygen supply level, while the growth of the wild type strains, KT2440 and KT2442, followed the typical sigmoidal evolution that could be described by the logistic equation. The presence of outer membrane vesicles has been observed in the GMO strains. When the cultures were conducted at low stirrer speed, and so at low oxygen transfer rate, these vesicles were detected, indicating the bacterial response to oxidative stress, caused by the catalytic activity of the HpaC enzyme. For all of the strains tested, no hydrodynamic stress has been detected, even at very high agitation levels. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:900-909, 2018.

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Factors Affecting the Biodesulfurization Process

2018

Biodesulfurization in Petroleum Refining

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Influence of oxygen transfer on Pseudomonas putida effects on growth rate and biodesulfurization capacity

Cited by 21 publications

References 31 publications

Effect of fluid dynamic conditions on 2,3‐butanediol production by Raoultella terrigena in SBTR: oxygen transfer and uptake rates

Effect of fluid dynamic conditions on 2,3‐butanediol production by Raoultella terrigena in SBTR: oxygen transfer and uptake rates

Behavior of several pseudomonas putida strains growth under different agitation and oxygen supply conditions

Factors Affecting the Biodesulfurization Process

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