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Yajie Tang - One of the best experts on this subject based on the ideXlab platform.
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ORIGINAL PAPER Lycopene production from synthetic medium by Blakeslea trispora NRRL 2895 (+) and 2896 (2) in a stirred-tank fermenter
2016Co-Authors: Xiu-ji Liu, Rui-sang Liu, Yajie TangAbstract:Abstract The dissolved oxygen tension of 20 % of air saturation, pH-shift from 4.0 to 5.5 on day 3, and a mod-erate shear stress (calculated as an Impeller Tip Speed, VTip 0:926 2:161 m=s) were identified to be the key factors in scaling-up the mated fermentation of Blakeslea trispora NRRL 2895 (?) and 2896 (-) for lycopene production from a shake flask to a stirred-tank fermenter. The maximal lycopene production of 183.3 mg/L was obtained in 7.5-L stirred-tank fermenter, and then the mated fermentation process was successfully step-wise scaled-up from 7.5- to 200-L stirred-tank fermenter. The comparability of the fermentation process was well con-trolled and the lycopene production was maintained during the process scale-up. Furthermore, with the integrated addition of 150 lmol/L abscisic acid on day 3, 0.5 g/L leucine and 0.1 g/L penicillin on day 4, the highest lyco-pene production of 270.3 mg/L was achieved in the mated fermentation of B. trispora in stirred-tank fermenter
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lycopene production from synthetic medium by blakeslea trispora nrrl 2895 and 2896 in a stirred tank fermenter
Bioprocess and Biosystems Engineering, 2012Co-Authors: Hongmei Li, Yajie TangAbstract:The dissolved oxygen tension of 20% of air saturation, pH-shift from 4.0 to 5.5 on day 3, and a moderate shear stress (calculated as an Impeller Tip Speed, \( V_{\text{Tip}} = 0. 9 2 6- 2. 1 6 1 \, {\text{m}}/{\text{s}} \)) were identified to be the key factors in scaling-up the mated fermentation of Blakeslea trispora NRRL 2895 (+) and 2896 (−) for lycopene production from a shake flask to a stirred-tank fermenter. The maximal lycopene production of 183.3 mg/L was obtained in 7.5-L stirred-tank fermenter, and then the mated fermentation process was successfully step-wise scaled-up from 7.5- to 200-L stirred-tank fermenter. The comparability of the fermentation process was well controlled and the lycopene production was maintained during the process scale-up. Furthermore, with the integrated addition of 150 μmol/L abscisic acid on day 3, 0.5 g/L leucine and 0.1 g/L penicillin on day 4, the highest lycopene production of 270.3 mg/L was achieved in the mated fermentation of B. trispora in stirred-tank fermenter.
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Lycopene production from synthetic medium by Blakeslea trispora NRRL 2895 (+) and 2896 (-) in a stirred-tank fermenter.
Bioprocess and Biosystems Engineering, 2011Co-Authors: Xiu-ji Liu, Rui-sang Liu, Yajie TangAbstract:The dissolved oxygen tension of 20% of air saturation, pH-shift from 4.0 to 5.5 on day 3, and a moderate shear stress (calculated as an Impeller Tip Speed, \( V_{\text{Tip}} = 0. 9 2 6- 2. 1 6 1 \, {\text{m}}/{\text{s}} \)) were identified to be the key factors in scaling-up the mated fermentation of Blakeslea trispora NRRL 2895 (+) and 2896 (−) for lycopene production from a shake flask to a stirred-tank fermenter. The maximal lycopene production of 183.3 mg/L was obtained in 7.5-L stirred-tank fermenter, and then the mated fermentation process was successfully step-wise scaled-up from 7.5- to 200-L stirred-tank fermenter. The comparability of the fermentation process was well controlled and the lycopene production was maintained during the process scale-up. Furthermore, with the integrated addition of 150 μmol/L abscisic acid on day 3, 0.5 g/L leucine and 0.1 g/L penicillin on day 4, the highest lycopene production of 270.3 mg/L was achieved in the mated fermentation of B. trispora in stirred-tank fermenter.
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Scale-up study on the fed-batch fermentation of Ganoderma lucidum for the hyperproduction of ganoderic acid and Ganoderma polysaccharides
Process Biochemistry, 2010Co-Authors: Yajie Tang, Wei Zhang, Rui-sang Liu, Li-wen Zhu, Jian-jiang ZhongAbstract:Besides the identified key factors of pH-shift from 3.0 to 4.5 on day 4 and dissolved oxygen tension (DOT) shift from 25 to 10% on day 6, lower shear stress was also demonstrated to be a key factor in scaling-up the fed-batch fermentation of the medicinal mushroom Ganoderma lucidum from a shake flask to a stirred-tank bioreactor. The maximal biomass (22.62 g/L), intercellular polysaccharide production (4.74 g/L), and ganoderic acid production (798.0 mg/L) were attained at a low Impeller Tip Speed of 1.234 m/s. Based on the identified key factors of pH-shift, DOT-shift and lower shear stress, the fed-batch fermentation of G. lucidum was successfully step-wise scaled-up from 7.5- to 200-L stirred-tank bioreactor. Through the qualitative and quantitative side-by-side comparison of G. lucidum growth and metabolites accumulation, it was concluded that the comparability of the fed-batch fermentation process were well controlled and the products were maintained during the process scale-up.
D.f. Long - One of the best experts on this subject based on the ideXlab platform.
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the evolution of granule fracture strength as a function of Impeller Tip Speed and granule size for a novel reverse phase wet granulation process
International Journal of Pharmaceutics, 2015Co-Authors: Jonathan B. Wade, Gary P. Martin, D.f. LongAbstract:Abstract The feasibility of a novel reverse-phase wet granulation process has been established previously and several potential advantages over the conventional process have been highlighted ( Wade et al., 2014a , Wade et al., 2014b , Wade et al., 2014b ). Due to fundamental differences in the growth mechanism and granule consolidation behaviour between the two processes the reverse-phase approach generally formed granules with a greater mass mean diameter and a lower intragranular porosity than those formed by the conventional granulation process under the same liquid saturation and Impeller Tip Speed conditions. The lower intragranular porosity was hypothesised to result in an increase in the granule strength and subsequent decrease in tablet tensile strength. Consequently, the aim of this study was to compare the effect of Impeller Tip Speed and granule size on the strength and compaction properties of granules prepared using both the reverse-phase and conventional granulation processes. For the conventional granulation process an increase in the Impeller Tip Speed from 1.57 to 4.71 m s −1 (200–600 RPM) resulted in an increase in the mean granule strength ( p p p > 0.05) on mean granule strength whereas, like the conventional process, an increase in granule size fraction from 425–600 to 2000–3350 μm resulted in a decrease ( p p > 0.05) for either granulation approach. These data support the rejection of the original hypothesis which stated that an increase in granule strength may result in a decrease in the tablet tensile strength. The similar tablet tensile strength observed between the conventional and reverse-phase granulation processes indicated that while mechanistic differences exist in the formation of the granules, which resulted in significant granule-scale fracture strength differences, the granule compaction properties at pharmaceutically relevant tableting pressures were unaffected.
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The evolution of granule fracture strength as a function of Impeller Tip Speed and granule size for a novel reverse-phase wet granulation process.
International journal of pharmaceutics, 2015Co-Authors: Jonathan B. Wade, Gary P. Martin, D.f. LongAbstract:The feasibility of a novel reverse-phase wet granulation process has been established previously and several potential advantages over the conventional process have been highlighted (Wade et al., 2014a,b,b). Due to fundamental differences in the growth mechanism and granule consolidation behaviour between the two processes the reverse-phase approach generally formed granules with a greater mass mean diameter and a lower intragranular porosity than those formed by the conventional granulation process under the same liquid saturation and Impeller Tip Speed conditions. The lower intragranular porosity was hypothesised to result in an increase in the granule strength and subsequent decrease in tablet tensile strength. Consequently, the aim of this study was to compare the effect of Impeller Tip Speed and granule size on the strength and compaction properties of granules prepared using both the reverse-phase and conventional granulation processes. For the conventional granulation process an increase in the Impeller Tip Speed from 1.57 to 4.71 ms(-1) (200-600 RPM) resulted in an increase in the mean granule strength (p
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Controlling granule size through breakage in a novel reverse-phase wet granulation process: the effect of Impeller Speed and binder liquid viscosity.
International Journal of Pharmaceutics, 2014Co-Authors: Jonathan B. Wade, Gary P. Martin, D.f. LongAbstract:Abstract The feasibility of a novel reverse-phase wet granulation process has been established previously highlighting several potential advantages over the conventional wet granulation process and making recommendations for further development of the approach. The feasibility study showed that in the reverse-phase process granule formation proceeds via a controlled breakage mechanism. Consequently, the aim of the present study was to investigate the effect of Impeller Speeds and binder liquid viscosity on the size distribution and intragranular porosity of granules using this novel process. Impeller Tip Speed was found to have different effects on the granules produced by a conventional as opposed to a reverse-phase granulation process. For the conventional process, an increase in Impeller Speed from 1.57 to 3.14 m s−1 had minimal effect on granule size distribution. However, a further increase in Impeller Tip Speed to 3.93 and 4.71 m s−1 resulted in a decrease in intragranular porosity and a corresponding increase in mean granule size. In contrast when the reverse-phase process was used, an increase in Impeller Speed from 1.57 to 4.71 m s−1 resulted in increased granule breakage and a decrease in the mean granule size. This was postulated to be due to the fact that the granulation process begins with fully saturated pores. Under these conditions further consolidation of granules at increased Impeller Tip Speeds is limited and rebound or breakage occurs. Based on these results and analysis of the modified capillary number the conventional process appears to be driven by viscous forces whereas the reverse-phase process appears to be driven by capillary forces. Additionally, in the reverse-phase process a critical Impeller Speed, represented by the equilibrium between centrifugal and gravitational forces, appears to represent the point above which breakage of large wet agglomerates and mechanical dispersion of binder liquid take place. In contrast the conventional process appears to be difficult to control due to variations in granule consolidation, which depends upon experimental variables. Such variations meant increased Impeller Tip Speed both decreased and increased granule size. The reverse-phase process appears to offer simple control over granule porosity and size through manipulation of the Impeller Speed and further evaluation of the approach is warranted.
Libor Labík - One of the best experts on this subject based on the ideXlab platform.
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volumetric mass transfer coefficient in viscous liquid in mechanically agitated fermenters measurement and correlation
Chemical Engineering Science, 2017Co-Authors: Libor Labík, Tomáš Moucha, Radim Petřicek, J F Rejl, L Valenz, Jan HaidlAbstract:Abstract In the industrial fermentation processes, most liquids are non-coalescent and often exhibit increased viscosity. However, due to the limitations of most measurement methods, there is a lack of reliable data for predicting volumetric mass transfer coefficients ( k L a ) for viscous batches, especially under high dissipated energies, as the accurate determination of oxygen concentration profile in viscous liquids is not as easy as in low viscosity ones. Our goal is to develop reliable technique for k L a determination in viscous liquids and to establish suitable correlation shapes to describe k L a data. We used the dynamic pressure method (DPM), the experimental set-up of which has been modified for the measurement in viscous liquids. Dissolved oxygen (DO) probes were placed in bypass measuring cells. This set up brings well defined transient characteristics of DO probes, which is crucial for correct k L a evaluation. Measurements were conducted in two phase mulTiple-Impeller fermenters with a non-coalescent viscous Newtonian batch under a wide range of experimental conditions and in the apparatuses of two scales. Using pure oxygen as gas phase, it was confirmed that DPM yields k L a ’s independent of the driving force of absorption even in viscous batch. The improved set up of DPM enabled to use also optical DO probes as well as polarographic ones. It was confirmed that optical DO probe can be used for k L a values up to 0.4 s −1 . Based on the experimental data, correlations were developed to predict k L a in industrial fermenters. Standard correlation k L a = 2.99 ⋅ 10 −3 ⋅( P g / V L ) 0.891 v s 0.556 with standard deviation, SD, 30%, based on gassed power input P g and superficial gas velocity v s , has low standard deviation but it is scale specific. On the other hand, when the term of Impeller Tip Speed ( ND ) is used instead of P g , predicted data exhibit neither over- nor under-estimation of k L a for particular apparatus scale; so the effect of the vessel scale is properly described using this term. In addition, the Impeller power number P o was found to be a reliable predictor of k L a in a common correlation for various Impeller types, when used together with the Impeller Tip Speed term. The correlation k L a = 0.295⋅( ND ) 2.083 v s 0.461 P o 0.737 with SD 28% suggested in this work can be used for fairly accurate design of industrial fermenters. Both the experimental technique and the correlation shape are ready to be used to obtain the design tool for other batches with various viscosities.
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Volumetric mass transfer coefficient in mulTiple-Impeller gas–liquid contactors. Scaling-up study for various Impeller types
Chemical Engineering Journal, 2014Co-Authors: Libor Labík, Radek Vostal, Tomáš Moucha, F.j. Rejl, M. KordačAbstract:Abstract Focused on liquid film-controlled processes in mechanically agitated aerated vessels, an attempt is made to develop scale-up correlations based on isotropic turbulence theory. It is shown that including the Impeller Tip Speed fD (Impeller frequency * Impeller diameter) in data treatment significantly improves the volumetric mass transfer coefficient ( k L a ) prediction abilities in scaling-up applications. Additionally, simplified correlation is developed, which evades the need of Impeller power knowledge. Its good usability for k L a prediction is shown except for the case when common correlation is made together for axial and radial Impellers. The study is based on measurements of volumetric mass transfer coefficient in a pilot scale mulTiple-Impeller vessel with non-coalescent batch and six various Impeller types, which expand previous data set from a laboratory scale tank.
Jan Haidl - One of the best experts on this subject based on the ideXlab platform.
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volumetric mass transfer coefficient in viscous liquid in mechanically agitated fermenters measurement and correlation
Chemical Engineering Science, 2017Co-Authors: Libor Labík, Tomáš Moucha, Radim Petřicek, J F Rejl, L Valenz, Jan HaidlAbstract:Abstract In the industrial fermentation processes, most liquids are non-coalescent and often exhibit increased viscosity. However, due to the limitations of most measurement methods, there is a lack of reliable data for predicting volumetric mass transfer coefficients ( k L a ) for viscous batches, especially under high dissipated energies, as the accurate determination of oxygen concentration profile in viscous liquids is not as easy as in low viscosity ones. Our goal is to develop reliable technique for k L a determination in viscous liquids and to establish suitable correlation shapes to describe k L a data. We used the dynamic pressure method (DPM), the experimental set-up of which has been modified for the measurement in viscous liquids. Dissolved oxygen (DO) probes were placed in bypass measuring cells. This set up brings well defined transient characteristics of DO probes, which is crucial for correct k L a evaluation. Measurements were conducted in two phase mulTiple-Impeller fermenters with a non-coalescent viscous Newtonian batch under a wide range of experimental conditions and in the apparatuses of two scales. Using pure oxygen as gas phase, it was confirmed that DPM yields k L a ’s independent of the driving force of absorption even in viscous batch. The improved set up of DPM enabled to use also optical DO probes as well as polarographic ones. It was confirmed that optical DO probe can be used for k L a values up to 0.4 s −1 . Based on the experimental data, correlations were developed to predict k L a in industrial fermenters. Standard correlation k L a = 2.99 ⋅ 10 −3 ⋅( P g / V L ) 0.891 v s 0.556 with standard deviation, SD, 30%, based on gassed power input P g and superficial gas velocity v s , has low standard deviation but it is scale specific. On the other hand, when the term of Impeller Tip Speed ( ND ) is used instead of P g , predicted data exhibit neither over- nor under-estimation of k L a for particular apparatus scale; so the effect of the vessel scale is properly described using this term. In addition, the Impeller power number P o was found to be a reliable predictor of k L a in a common correlation for various Impeller types, when used together with the Impeller Tip Speed term. The correlation k L a = 0.295⋅( ND ) 2.083 v s 0.461 P o 0.737 with SD 28% suggested in this work can be used for fairly accurate design of industrial fermenters. Both the experimental technique and the correlation shape are ready to be used to obtain the design tool for other batches with various viscosities.
Jonathan B. Wade - One of the best experts on this subject based on the ideXlab platform.
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the evolution of granule fracture strength as a function of Impeller Tip Speed and granule size for a novel reverse phase wet granulation process
International Journal of Pharmaceutics, 2015Co-Authors: Jonathan B. Wade, Gary P. Martin, D.f. LongAbstract:Abstract The feasibility of a novel reverse-phase wet granulation process has been established previously and several potential advantages over the conventional process have been highlighted ( Wade et al., 2014a , Wade et al., 2014b , Wade et al., 2014b ). Due to fundamental differences in the growth mechanism and granule consolidation behaviour between the two processes the reverse-phase approach generally formed granules with a greater mass mean diameter and a lower intragranular porosity than those formed by the conventional granulation process under the same liquid saturation and Impeller Tip Speed conditions. The lower intragranular porosity was hypothesised to result in an increase in the granule strength and subsequent decrease in tablet tensile strength. Consequently, the aim of this study was to compare the effect of Impeller Tip Speed and granule size on the strength and compaction properties of granules prepared using both the reverse-phase and conventional granulation processes. For the conventional granulation process an increase in the Impeller Tip Speed from 1.57 to 4.71 m s −1 (200–600 RPM) resulted in an increase in the mean granule strength ( p p p > 0.05) on mean granule strength whereas, like the conventional process, an increase in granule size fraction from 425–600 to 2000–3350 μm resulted in a decrease ( p p > 0.05) for either granulation approach. These data support the rejection of the original hypothesis which stated that an increase in granule strength may result in a decrease in the tablet tensile strength. The similar tablet tensile strength observed between the conventional and reverse-phase granulation processes indicated that while mechanistic differences exist in the formation of the granules, which resulted in significant granule-scale fracture strength differences, the granule compaction properties at pharmaceutically relevant tableting pressures were unaffected.
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The evolution of granule fracture strength as a function of Impeller Tip Speed and granule size for a novel reverse-phase wet granulation process.
International journal of pharmaceutics, 2015Co-Authors: Jonathan B. Wade, Gary P. Martin, D.f. LongAbstract:The feasibility of a novel reverse-phase wet granulation process has been established previously and several potential advantages over the conventional process have been highlighted (Wade et al., 2014a,b,b). Due to fundamental differences in the growth mechanism and granule consolidation behaviour between the two processes the reverse-phase approach generally formed granules with a greater mass mean diameter and a lower intragranular porosity than those formed by the conventional granulation process under the same liquid saturation and Impeller Tip Speed conditions. The lower intragranular porosity was hypothesised to result in an increase in the granule strength and subsequent decrease in tablet tensile strength. Consequently, the aim of this study was to compare the effect of Impeller Tip Speed and granule size on the strength and compaction properties of granules prepared using both the reverse-phase and conventional granulation processes. For the conventional granulation process an increase in the Impeller Tip Speed from 1.57 to 4.71 ms(-1) (200-600 RPM) resulted in an increase in the mean granule strength (p
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Controlling granule size through breakage in a novel reverse-phase wet granulation process: the effect of Impeller Speed and binder liquid viscosity.
International Journal of Pharmaceutics, 2014Co-Authors: Jonathan B. Wade, Gary P. Martin, D.f. LongAbstract:Abstract The feasibility of a novel reverse-phase wet granulation process has been established previously highlighting several potential advantages over the conventional wet granulation process and making recommendations for further development of the approach. The feasibility study showed that in the reverse-phase process granule formation proceeds via a controlled breakage mechanism. Consequently, the aim of the present study was to investigate the effect of Impeller Speeds and binder liquid viscosity on the size distribution and intragranular porosity of granules using this novel process. Impeller Tip Speed was found to have different effects on the granules produced by a conventional as opposed to a reverse-phase granulation process. For the conventional process, an increase in Impeller Speed from 1.57 to 3.14 m s−1 had minimal effect on granule size distribution. However, a further increase in Impeller Tip Speed to 3.93 and 4.71 m s−1 resulted in a decrease in intragranular porosity and a corresponding increase in mean granule size. In contrast when the reverse-phase process was used, an increase in Impeller Speed from 1.57 to 4.71 m s−1 resulted in increased granule breakage and a decrease in the mean granule size. This was postulated to be due to the fact that the granulation process begins with fully saturated pores. Under these conditions further consolidation of granules at increased Impeller Tip Speeds is limited and rebound or breakage occurs. Based on these results and analysis of the modified capillary number the conventional process appears to be driven by viscous forces whereas the reverse-phase process appears to be driven by capillary forces. Additionally, in the reverse-phase process a critical Impeller Speed, represented by the equilibrium between centrifugal and gravitational forces, appears to represent the point above which breakage of large wet agglomerates and mechanical dispersion of binder liquid take place. In contrast the conventional process appears to be difficult to control due to variations in granule consolidation, which depends upon experimental variables. Such variations meant increased Impeller Tip Speed both decreased and increased granule size. The reverse-phase process appears to offer simple control over granule porosity and size through manipulation of the Impeller Speed and further evaluation of the approach is warranted.
