Effects of the hydrodynamic environment and oxygen mass transfer on plant cell growth and milk‐clotting protease production in a stirred‐tank reactor

Raposo, Sara; Lima-Costa, Maria Emília

doi:10.1002/elsc.201100087

Cited by 8 publications

(12 citation statements)

References 26 publications

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“…Selection of the proper process parameters (for example power consumption or gas hold-up) which characterise the mixing operation in the agitated vessel allows to ensure appropriate conditions for conducting chemical and biochemical processes (Garcia-Ochoa and Gomez, 2009;Martin et al 2008a,b;Montante et al, 2007Montante et al, , 2008Raposo and Lima-Costa, 2012;Scargiali et al, 2007;Van't Riet, 1975).…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamic Characteristics of Mechanically Agitated Air - Aqueous Sucrose Solutions

Cudak

2014

Chemical and Process Engineering

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The aim of the research presented in this paper was determination of power consumption and gas hold-up in mechanically agitated aerated aqueous low concentration sucrose solutions. Experimental studies were conducted in a vessel of diameter 0.634 m equipped with high-speed impellers (Rushton turbine, Smith turbine or A 315). The following operating parameters were changed: volumetric gas flow rate (expressed by superficial gas velocity), impeller speed, sucrose concentration and type of impeller. Based on the experiments results, impellers with a modified shape of blades, e.g. CD 6 or A 315, could be recommended for such gas-liquid systems. Power consumption was measured using strain gauge method. The results of gas holdup measurements have been approximated by an empirical relationship containing dimensionless numbers (Eq. (2)).

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Section: Introductionmentioning

confidence: 99%

Hydrodynamic Characteristics of Mechanically Agitated Air - Aqueous Sucrose Solutions

Cudak

2014

Chemical and Process Engineering

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“…Studies by Raposo et al [53] showed that this type of sparger is more efficient with high K L a values than those obtained with the L-shaped sparger. The porous sparger promotes the formation of microbubbles with a high retention time in the liquid phase, thus enabling a greater mass transfer of oxygen and consequently a greater accessibility of this gas to the cells.…”

Section: Effect Of Oxygen Availability In Lipid Accumulation (High Aementioning

confidence: 88%

A new combined approach to improved lipid production using a strictly aerobic and oleaginous yeast

Guerreiro

Constantino

Lima-Costa

et al. 2018

Engineering in Life Sciences

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Microbial lipids have potential applications in energy, and food industry, because most of those lipids are triacylglycerol with long‐chain fatty‐acids that are comparable to conventional vegetable oils and can be obtained without arable land requirement. Rhodosporidium toruloides is a strictly aerobic strain, where oxygen plays a crucial role in growth, maintenance, and metabolite production, such as lipids and carotenoids. Dissolved oxygen concentration is one of the major factors affecting yeast physiological and biochemical characteristics. In this context, different approaches have been developed to increase available oxygen by the increasing the aeration and the addition of an oxygen‐vector. The growth of R. toruloides in 2‐L mechanical stirred tank reactor equipped with 1 or 2 porous spargers and a 70 C/N ratio, revealed a lipid content of 0.47 and 0.52 g/g and a lipidic productivity of 0.16 and 0.17 g/L day, respectively. The oxygen‐vector addition, increased the lipidic productivity for 0.20 g/L day and a lipid contend of 0.51 g of lipids/g of biomass. The combined approach, combining high aeration (AA), and 1% of n‐dodecane addition (DA), produced a significant improvement in the lipid accumulation (62%, w/w), when compared with the DA (51%, w/w) and the AA (52%, w/w) approaches. The increasing of lipids accumulation and smaller culture time are key factors for the success of scale‐up and profitability of a bioprocess.

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“…Impeller tip speed ( ν i ) expressed in m/s was calculated according to Equation described by Raposo and LimaCosta :

ν_{i} = π \times N \times D i,

where N is the rotational speed of the impeller (1/s) and Di is the impeller diameter (0.05 m). The average energy dissipation rate ( ε ), expressed in kW/kg is the specific power input (kW/m 3 ) ( P / V ) divided by the density of the culture, that is, ρ (1.018 kg/m 3 ), according to Equation :

ε = P / ρ V = N p N^{3} D_{i}^{5} / V,

where N is the rotational speed of the impeller (1/s), Di is the impeller diameter (0.05 m), Np is the power number for the relevant impeller at the prevailing value of the Reynolds number ([ ND i 2 p ] /μ app ), and v is the dissipation of medium volume.…”

Section: Methodsmentioning

confidence: 99%

Production of anti‐inflammatory compounds in Sphaeralcea angustifolia cell suspension cultivated in stirred tank bioreactor

Pérez-Hernández

Nicasio-Torres

Sarmiento-López

et al. 2019

Engineering in Life Sciences

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Sphaeralcea angustifolia is a plant used for the treatment of inflammatory processes. Scopoletin, tomentin, and sphaeralcic acid were identified as the compounds with anti‐inflammatory and immunomodulatory effects. Successful establishment of the cell culture in Erlenmeyer flasks has been reported previously. The aim of this study was to evaluate the ability of cells in suspension from S. angustifolia grown in a stirred tank bioreactor and demonstrate their capacity to produce bioactive compounds. Cells in suspension grown at 200 rpm reached a maximal cell biomass in dry weight at 19.11 g/L and produced 3.47 mg/g of sphaeralcic acid. The mixture of scopoletin and tomentin was only detected at the beginning of the culture (12.13 μg/g). Considering that the profile of dissolved oxygen during the cultures was lesser than 15%, it is possible that the low growth at 100 rpm could be due to oxygen limitations or to cell sedimentation. At 400 rpm, a negative effect on cell viability could be caused by the increase in the hydrodynamic stress, including the impeller tip, average shear rate, and Reynolds number. The sphaeralcic acid content in the cell suspension of S. angustifolia obtained in the bioreactor was two orders of magnitude greater than that reported for the culture grown in Erlenmeyer flasks.

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Effects of the hydrodynamic environment and oxygen mass transfer on plant cell growth and milk‐clotting protease production in a stirred‐tank reactor

Cited by 8 publications

References 26 publications

Hydrodynamic Characteristics of Mechanically Agitated Air - Aqueous Sucrose Solutions

Hydrodynamic Characteristics of Mechanically Agitated Air - Aqueous Sucrose Solutions

A new combined approach to improved lipid production using a strictly aerobic and oleaginous yeast

Production of anti‐inflammatory compounds in Sphaeralcea angustifolia cell suspension cultivated in stirred tank bioreactor

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