Establishment of the Carrot-Made LTB-Syn Antigen Cell Line in Shake Flask and Airlift Bioreactor Cultures

Carrot (Daucus carota) cells have been used to effectively manufacture recombinant biopharmaceuticals such as cytokines, vaccines, and antibodies. We generated the carrot cell line Z4, genetically modified to produce the LTB-Syn antigen, which is a fusion protein proposed for immunotherapy against synucleinopathies. In this work, the Z4 cell suspension line was cultivated to produce the LTB-Syn protein in a 250 mL shake flask and 2 L airlift bioreactor cultures grown for 45 and 30 days, respectively. Maximum biomass was obtained on day 15 in both the airlift bioreactor (35.00 ± 0.04 g/L DW) and shake flasks (17.00 ± 0.04 g/L DW). In the bioreactor, the highest LTB-Syn protein yield (1.52 ± 0.03 µg/g FW) was obtained on day 15; while the same occurred on day 18 for shake flasks (0.92 ± 0.02 µg/g FW). LTB-Syn protein levels were analyzed by GM1-ELISA and western blot. PCR analysis confirmed the presence of the transgene in the Z4 line. The obtained data demonstrate that the carrot Z4 cell suspension line grown in airlift bioreactors shows promise for a scale-up cultivation producing an oral LTB-Syn antigen.

Potentials of utilizing renewable resources of agriculture residues for the biosynthesis of bacterial cellulose nanofibers

In the present study, production of bacterial cellulose nanofibers from single sugars and sugar mixtures in feedstock was investigated using different culture methods. This includes production in shake flask, stirred tank and draft tube airlift bioreactors. There has been no previous work done other than this reported work concerning production of bacterial cellulose nanofibers using sugar mixtures. Fructose was found to be the top producer with 5.65 g/L of bacterial cellulose nanofibers. The different compositions of sugar mixtures tested in this study were identical to acid hydrolyzates of agricultural residues. Maximum yield of 17.72 g/L was observed with mixture that resembles the acid hydrolyzate of wheat straw. Modified stirred tank and airlift bioreactors showed higher production of bacterial cellulose nanofibers compared to shake flask. In general, results obtained in the present study demonstrate potential of improving production of nanofibers solely based on agricultural residues and using draft tube airlift bioreactors.

Potentials of utilizing renewable resources of agriculture residues for the biosynthesis of bacterial cellulose nanofibers

In the present study, production of bacterial cellulose nanofibers from single sugars and sugar mixtures in feedstock was investigated using different culture methods. This includes production in shake flask, stirred tank and draft tube airlift bioreactors. There has been no previous work done other than this reported work concerning production of bacterial cellulose nanofibers using sugar mixtures. Fructose was found to be the top producer with 5.65 g/L of bacterial cellulose nanofibers. The different compositions of sugar mixtures tested in this study were identical to acid hydrolyzates of agricultural residues. Maximum yield of 17.72 g/L was observed with mixture that resembles the acid hydrolyzate of wheat straw. Modified stirred tank and airlift bioreactors showed higher production of bacterial cellulose nanofibers compared to shake flask. In general, results obtained in the present study demonstrate potential of improving production of nanofibers solely based on agricultural residues and using draft tube airlift bioreactors.

Mixing Characteristics of External Loop Airlift Bioreactor using Electrical Resistance Tomography

In the present work, a novel packed bed external loop pneumatically agitated airlift bioreactor with an internal gas distributor (perforated plate) between two rolls of packing in the riser was designed and built. This novel approach combines advantages of packed bed and external loop airlift bioreactors. The main objective of this research work was to characterize the hydrodynamic performance of this novel reactor through a non-intrusive flow visualization technique called electrical resistance tomography (ERT). The tomography images, which were generated using a linear back projection algorithm, were employed to explore the effects of different design parameters and operating conditions. These include the effect of the two packing in the riser and the internal gas distributor (perforated plate) installed between the two packing. Other parameters investigated include the effect of sparger configuration, gas flow rate, and liquid height in the bioreactor on the different hydrodynamic parameters such as gas holdup, mixing time, and liquid circulation velocity. Results showed that the gas holdup and mixing time increased in the presence of the gas distributor, while the riser superficial liquid velocity was decreased. Furthermore, gas holdup and mixing time increased, superficial liquid velocity decreased when decreasing liquid height in the reactor, and when using packing or gas distributor between two packings in the riser. These results can be used to improve mixing characteristics in external loop airlift bioreactors for wider range of applications.

Mixing Characteristics of External Loop Airlift Bioreactor using Electrical Resistance Tomography

In the present work, a novel packed bed external loop pneumatically agitated airlift bioreactor with an internal gas distributor (perforated plate) between two rolls of packing in the riser was designed and built. This novel approach combines advantages of packed bed and external loop airlift bioreactors. The main objective of this research work was to characterize the hydrodynamic performance of this novel reactor through a non-intrusive flow visualization technique called electrical resistance tomography (ERT). The tomography images, which were generated using a linear back projection algorithm, were employed to explore the effects of different design parameters and operating conditions. These include the effect of the two packing in the riser and the internal gas distributor (perforated plate) installed between the two packing. Other parameters investigated include the effect of sparger configuration, gas flow rate, and liquid height in the bioreactor on the different hydrodynamic parameters such as gas holdup, mixing time, and liquid circulation velocity. Results showed that the gas holdup and mixing time increased in the presence of the gas distributor, while the riser superficial liquid velocity was decreased. Furthermore, gas holdup and mixing time increased, superficial liquid velocity decreased when decreasing liquid height in the reactor, and when using packing or gas distributor between two packings in the riser. These results can be used to improve mixing characteristics in external loop airlift bioreactors for wider range of applications.

CO2 Capture of the Gas Emission, Using a Catalytic Converter and Airlift Bioreactors with the Microalga Scenedesmus dimorphus

A process composed by a catalytic converter and three sequential Airlift photobioreactors containing the microalga Scenedesmus dimorphus was studied to capture CO2, NOx, and CO from emissions of a steam boiler which was burning diesel. The catalytic converter transformed to CO2 a maximum of 78% of the CO present in the combustion gas. The effects of shear rate, light intensity, and light/dark cycles on the biomass growth of the algae were studied. It was observed that at low shear rates (Re ≈ 3200), a high productivity of 0.29 gcel L−1 d−1 was obtained. When the microalga was exposed to 60.75 µmol·m−2·s−1 of intensity of light and a light/dark cycle of 16/8 h, a maximum productivity of 0.44 gcel L−1 d−1 and a maximum CO2 fixation rate 0.8 g CO2 L−1·d−1 were obtained. The maximum CO2 removal efficiency was 64.3%, and KLa for CO2 and O2 were 1.2 h−1 and 3.71 h−1 respectively.