Aeration and agitation

“…The larger the value of k L a , the higher is the bioreactor's aeration capacity (Stanbury et al . ). Moreover, external Venturi air systems have been shown to be effective devices for maximizing oxygen transfer (Ndoye et al .…”

Section: Introductionmentioning

confidence: 97%

Impact of high initial concentrations of acetic acid and ethanol on acetification rate in an internal Venturi injector bioreactor

2015

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“…Research and development are mainly being performed in the field of biopharmaceutical production processes using magnetically sealed bioreactors, where typical application volumes are 500 L for bacterial and 3000 L for mammalian cell cultures. The application of magnetically drives is limited by the viscosity of the culture broth (Matthews 2008) and the inability of the torque dependent power input to disperse gases and achieve homogeneity in the vessel (Stanbury et al 2017). The maximum possible torque is defined by the magnetic field strength and is independent of the motor power, meaning the coupling breaks when the load limit is exceeded (Dickey 2015).…”

Section: Seal Types: An Overviewmentioning

confidence: 99%

An overview of drive systems and sealing types in stirred bioreactors used in biotechnological processes

Schirmer

Maschke

Pörtner

et al. 2021

Appl Microbiol Biotechnol

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No matter the scale, stirred tank bioreactors are the most commonly used systems in biotechnological production processes. Single-use and reusable systems are supplied by several manufacturers. The type, size, and number of impellers used in these systems have a significant influence on the characteristics and designs of bioreactors. Depending on the desired application, classic shaft-driven systems, bearing-mounted drives, or stirring elements that levitate freely in the vessel may be employed. In systems with drive shafts, process hygiene requirements also affect the type of seal used. For sensitive processes with high hygienic requirements, magnetic-driven stirring systems, which have been the focus of much research in recent years, are recommended. This review provides the reader with an overview of the most common agitation and seal types implemented in stirred bioreactor systems, highlights their advantages and disadvantages, and explains their possible fields of application. Special attention is paid to the development of magnetically driven agitators, which are widely used in reusable systems and are also becoming more and more important in their single-use counterparts.Key Points• Basic design of the most frequently used bioreactor type: the stirred tank bioreactor• Differences in most common seal types in stirred systems and fields of application• Comprehensive overview of commercially available bioreactor seal types• Increased use of magnetically driven agitation systems in single-use bioreactors

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“…The main advantages of a bubble column bioreactor are the simplicity of construction and the excellent heat and mass transfer characteristics [28]. The main difference between a bubble column and an airlift reactor is that liquid circulation is achieved in the airlift in addition to that caused by the bubble flow [29]. Furthermore, according to the analysis of Humbrid et al [30], bubble column reactor systems can reduce the overall costs of oxygen delivery by 10-20% relative to stirred tanks.…”

Section: Introductionmentioning

confidence: 99%

Biodesulfurization of Dibenzothiophene and Its Alkylated Derivatives in a Two-Phase Bubble Column Bioreactor by Resting Cells of Rhodococcus erythropolis IGTS8

et al. 2021

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Biodesulfurization (BDS) is considered a complementary technology to the traditional hydrodesulfurization treatment for the removal of recalcitrant sulfur compounds from petroleum products. BDS was investigated in a bubble column bioreactor using two-phase media. The effects of various process parameters, such as biocatalyst age and concentration, organic fraction percentage (OFP), and type of sulfur compound—namely, dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and 4,6-diethyldibenzothiophene (4,6-DEDBT)—were evaluated, using resting cells of Rhodococcus erythropolis IGTS8. Cells derived from the beginning of the exponential growth phase of the bacterium exhibited the highest biodesulfurization efficiency and rate. The biocatalyst performed better in an OFP of 50% v/v. The extent of DBT desulfurization was dependent on cell concentration, with the desulfurization rate reaching its maximum at intermediate cell concentrations. A new semi-empirical model for the biphasic BDS was developed, based on the overall Michaelis-Menten kinetics and taking into consideration the deactivation of the biocatalyst over time, as well as the underlying mass transfer phenomena. The model fitted experimental data on DBT consumption and 2-hydroxibyphenyl (2-HBP) accumulation in the organic phase for various initial DBT concentrations and different organosulfur compounds. For constant OFP and biocatalyst concentration, the most important parameter that affects BDS efficiency seems to be biocatalyst deactivation, while the phenomenon is controlled by the affinities of biodesulfurizing enzymes for the different organosulfur compounds. Thus, desulfurization efficiency decreased with increasing initial DBT concentration, and in inverse proportion to increases in the carbon number of alkyl substituent groups.

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Aeration and agitation

Cited by 13 publications

References 119 publications

Impact of high initial concentrations of acetic acid and ethanol on acetification rate in an internal Venturi injector bioreactor

Impact of high initial concentrations of acetic acid and ethanol on acetification rate in an internal Venturi injector bioreactor

An overview of drive systems and sealing types in stirred bioreactors used in biotechnological processes

Biodesulfurization of Dibenzothiophene and Its Alkylated Derivatives in a Two-Phase Bubble Column Bioreactor by Resting Cells of Rhodococcus erythropolis IGTS8

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