Retrofit of CD-6 (Smith) Impeller in Fermentation Vessels

Junker, Beth; Mann, Zorina; Hunt, Graham R.

doi:10.1385/abab:89:1:67

Cited by 21 publications

(16 citation statements)

References 11 publications

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“…Specifically, greater ventilation has been shown to improve the inosine titer by nearly 20% in Bacillus fermentations (Ishizaki et al, 1973). Initial high and low ranges of airflow and agitation were varied over the course of development to determine their impact on C T and R. In addition, different agitation rates and impeller types (Junker et al, 2000) were compared.…”

Section: Ventilation and Agitation Ratementioning

confidence: 99%

“…Peak agitation rates for the different strains were compared using different impellers (hydrofoil Maxflo T, Rushton, Junker et al, 2000) (Table VIb). For MF4649, growth was slower using hydrofoil rather than Rushton impellers, but the peak gassed power draw was higher with hydrofoil impellers, indirectly suggesting a more filamentous morphology.…”

Section: Wild-type Versus Mutants Strainsmentioning

confidence: 99%

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Production of indole diterpenes by Aspergillus alliaceus

Junker

Walker

Connors

et al. 2006

Biotech & Bioengineering

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Production of two related indole diterpenes (differing by a dimethyl leucine side chain) by Aspergillus alliaceus was improved through several pilot scale fermentations. Media were optimized through focus primarily on initial increases, as well as mid-cycle additions, of carbon and nitrogen sources. Fermentation conditions were improved by varying ventilation conditions using various combinations of air flowrate and back-pressure set points. Production improvements were quantified based on total indole diterpene concentration as well as the ratio of the major-to-minor by-product components. Those changes with a positive substantial impact primarily on total indole diterpene concentration included early cycle glycerol shots and enhanced ventilation conditions (high air flowrate, low back-pressure). Those changes with a significant impact primarily on ratio included higher initial cerelose, soybean oil, monosodium glutamate, tryptophan, or ammonium sulfate concentrations, higher broth pH, and enhanced ventilation conditions. A few changes (higher initial glycerol and monosodium glutamate concentrations) resulted in less notable and desirable titer or ratio changes when implemented individually, but they were adopted to more fully realize the impact of other improvements or to simplify processing. Overall, total indole diterpene titers were improved at the 600 L pilot scale from 125-175 mg/L with a ratio of about 2.1 to 200-260 mg/L with a ratio of about 3.3-4.5. Thus, the ability to optimize total indole diterpene titer and/or ratio readily exists for secondary metabolite production using Aspergillus cultures.

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Section: Ventilation and Agitation Ratementioning

confidence: 99%

Section: Wild-type Versus Mutants Strainsmentioning

confidence: 99%

Production of indole diterpenes by Aspergillus alliaceus

Junker

Walker

Connors

et al. 2006

Biotech & Bioengineering

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“…Gas dispersion in the liquid phase in the agitated vessel equipped with a turbine disc impeller with curved blades was experimentally analysed by Cudak (2011Cudak ( , 2014; Musiał et al (2015); Rielly et al (1992); Sensel et al (1993); Smith and Katsanevakis (1993); Van't Riet et al (1976); Warmoeskerken and Smith (1989) and Zhengming et al (1991). Junker et al (2000) experimentally examined dual impeller combinations of CD 6 impeller in fermentation vessels. They stated that the use of dual CD 6 impellers and hybrids containing the CD 6 impeller decreases power consumption and increases mass transfer rate in the gas -liquid system compared to results obtained for systems equipped with dual Rushton turbines.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of momentum transfer processes in a mechanically agitated air – biophase – liquid system

Musiał¹,

Cudak²,

Karcz³

2017

Chemical and Process Engineering

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The results of numerical computations concerning momentum transfer processes in an air -biophase -liquid system agitated in a bioreactor equipped with baffles and a Smith turbine (CD 6 impeller) are presented in this paper. The effect of sucrose concentration on the distributions of the velocity of the continuous phase, gas hold-up and the size of gas bubbles in the system was analysed. Simulation results were presented in the form of the contours of the analysed magnitudes. The effect of sucrose concentration on the averaged values (i.e. determined on the basis of local values) of gas hold-up and gas bubbles size was evaluated. The results of the numerical computations of gas holdup were compared with our own experimental data.

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“…Besides this Rushton turbine turns out to be a poor gas handler at high aeration rates, they experience significant power drop upon gassing which influences the mass transfer. Disk turbines with curved blades are extensively studied [1,8,9].They are found to be better gas handlers and experience lesser loss in power upon aeration. This blade shape also contributes to lesser cavity formation behind the blades and hence improves the mass transfer capabilities.…”

Section: Introductionmentioning

confidence: 99%