Research Article
CO2 Control Strategy for Large-Scale Cell Culture Bioreactor Operation
Naveenganesh Muralidharan*,
Thatsinee Johnson,
Emma Bolduc,
Mark Davis
Issue:
Volume 12, Issue 1, April 2024
Pages:
1-13
Received:
3 January 2024
Accepted:
17 January 2024
Published:
1 February 2024
Abstract: In most mammalian cell culture operations, the pH is targeted to be close to neutral and the dissolved carbon dioxide [dCO2] concentration is desired to remain between 5 and 15% to avoid any inhibitory effects on cell growth. Typical cell culture scale-up approaches include maintaining constant power by volume (P/V) or a constant tip speed to set the impeller agitation rate or constant vvm to set the gas flow rate. However, these approaches are only focused on keeping the shear in the bioreactor system to a minimum and do not account for controlling the [dCO2] concentration within the desired range. Process engineers across industries have remediated the elevated [dCO2] concentration problem in large scale bioreactors by increasing gas flow rates; however, this approach is often trial and error. Therefore, in this article we review the current understanding of various factors that impact the dCO2 concentration during the scale up of the cell culture process to large-scale bioreactors. This article also describes an easy and practical approach to predict and control the dCO2 concentration in large-scale cell culture bioreactors using a mathematical predictive model developed based on mass-transfer first principles. We demonstrate the effective application and verification of the model by running a CHO cell culture process with a peak cell density of up to 20 x106 Cells/mL in a 15,000 L bioreactor working volume.
Abstract: In most mammalian cell culture operations, the pH is targeted to be close to neutral and the dissolved carbon dioxide [dCO2] concentration is desired to remain between 5 and 15% to avoid any inhibitory effects on cell growth. Typical cell culture scale-up approaches include maintaining constant power by volume (P/V) or a constant tip speed to set t...
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Research Article
Addition Ammonia Assimilation Bacteria to a Biofloc System for Japanese Eel (Anguilla japonica) Farming, Comparison of Growth Performance and Water Quality
Chang-gon Sin,
Yong-jin Ri,
Chol Kim,
Song-guk Rim,
Su-chol Rim,
Hui-won Kim*
Issue:
Volume 12, Issue 1, April 2024
Pages:
14-18
Received:
19 December 2023
Accepted:
10 January 2024
Published:
5 February 2024
Abstract: Biofloc technology (BFT) system is a renovated and promising aquaculture system which allows aquaculture animals to be farmed at a high density with little or zero water exchange. The research objective of this study was to investigate and compare the effect of BFT with and without exogenous ammonia assimilation bacteria supplementation on water quality and Japanese eel growth performance. Two biofloc treatments (BFT groups) with and without Bacillus sp. addition (Group A and B, respectively) and one control (Group C, traditional aquaculture) were created. Corn starch and sodium bicarbonate were added regularly to maintain C/N ratio and alkalinity of the biofloc treatments. Eels (30±1.2g) were stocked in each pond of 30m3 for 60 days. The result showed that although all toxic nitrogen compound concentration in BFT groups were maintained at safe levels for eel culture during the experiment, bacteria addition could help the system maintain lower level of ammonia at a beginning period. The higher weight gain and specific growth rate were observed in BFT groups compared to control group. Especially, ammonia assimilation bacteria addition had a positive impact on water quality and eel production as the Group A showed the highest total biomass of 129.09 kg with the lowest FCR (feed conversion ratio) of 1.78. The present study revealed that Japanese eels can be reared effectively by biofloc technology with exogenous bacteria input.
Abstract: Biofloc technology (BFT) system is a renovated and promising aquaculture system which allows aquaculture animals to be farmed at a high density with little or zero water exchange. The research objective of this study was to investigate and compare the effect of BFT with and without exogenous ammonia assimilation bacteria supplementation on water qu...
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Research Article
Correlation and Path Analysis for Agronomic and Processing Quality Traits of Potato (Solanum tuberosum L.) at Holetta, Central Ethiopia
Ebrahim Seid*,
Tesfaye Abebe
Issue:
Volume 12, Issue 1, March 2024
Pages:
19-28
Received:
29 December 2023
Accepted:
25 January 2024
Published:
21 February 2024
Abstract: Potato is the third most important food crop in terms of consumption in the world after rice and wheat. It is a nutrient-rich vegetable with just a small amount of fat and contains 16% carbohydrates, 2% proteins, 1% minerals, and 0.6% dietary fiber. The literature on path and correlation analysis and its application as a potato breeding tool is limited in comparison to its significance for processing purpose and the knowledge it adds for upcoming breeding work. The objective of this study was to determine the relation among tuber yield and processing quality traits of potato using correlation and path coefficient analysis. This experiment was conducted at Holetta Agricultural research Centre, Ethiopia during the main crop season of 2017. The experiment was laid out in randomized complete block design (RCBD) with three replications using 24 potato genotypes. Strong positive and significant correlation were found between total tuber yield and marketable tuber yield (r=0.98) at both genotypic and phenotypic levels. Stronger positive correlations were found between dry matter content and starch content (r= 1) and specific gravity (r=1). Path coefficient analysis of tuber yield and its components shows that dry matter content and marketable tuber yield exerted positive highest direct influence on total tuber yield. Specific gravity of tuber had high positive direct effect on dry matter content. So, to increase the performance of these traits for tuber yield and processing quality traits path analysis can be used. As a conclusion, most of the traits had positive correlations and direct effects with total tuber yield and dry matter content at phenotypic and genotypic levels. Therefore, those traits had practical importance in selection of potato genotypes for high total tuber yield and processing purpose.
Abstract: Potato is the third most important food crop in terms of consumption in the world after rice and wheat. It is a nutrient-rich vegetable with just a small amount of fat and contains 16% carbohydrates, 2% proteins, 1% minerals, and 0.6% dietary fiber. The literature on path and correlation analysis and its application as a potato breeding tool is lim...
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