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Your search keyword '"Luo, Hongzhen"' showing total 182 results
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182 results on '"Luo, Hongzhen"'

25. Optimization of the Process of Chinese Hamster Ovary (CHO) Cell Fed-Batch Culture to Stabilize Monoclonal Antibody Production and Overall Quality: Effect of pH Control Strategies.

Author

Liang, Kexue, Luo, Hongzhen, and Li, Qi

Subjects
PHARMACEUTICAL biotechnology industry, ANTIBODY formation, PH effect, MEDICAL research, MONOCLONAL antibodies
Abstract

Monoclonal antibodies (mAbs) used in biomedical research and therapeutic applications are primarily produced by Chinese hamster ovary (CHO) cells via fed-batch culture. The growing need for elevated quantities of biologics mandates the continual optimization of the mAb production process. The development of an effective process control method is indispensable for the production of specified mAbs by CHO cells. In this study, the effects of the pH control strategy on CHO cell fed-batch culture to produce an antibody (EA5) were first investigated in a 3 L bioreactor. The results indicate that controlling the culture pH at 7.2 during the fed-batch stage could produce a higher EA5 titer of 6.1 g/L with a lower Man5 ratio of 2.2% by day 14. Based on this, an optimized CHO cell fed-batch culture was conducted in a 15 L bioreactor to verify its effectiveness and stability. In this case, on day 14, an EA5 titer of 6.5 g/L was achieved with productivity of 0.46 g/L/day, which was 1.07-fold higher compared to that of the culture in the 3 L bioreactor. Furthermore, regarding the product quality, a monomer abundance of 96.0%, a main peak of 55.0%, and a Man5 proportion of 2.4% were maintained in the 15 L bioreactor. In addition, different cell clarification processes were evaluated using the CHO cell culture broth from the 3 L and 15 L bioreactors to further improve productivity and economic performance. Overall, this study provides some directions for process intensification and improving the quality of mAbs produced by CHO cells in the biopharmaceutical industry. [ABSTRACT FROM AUTHOR]

Published
2024
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36. In the quest for sustainable management of liquid fraction of manure - Insights from a life cycle assessment

Author

Ravi, Rahul, Beyers, Miriam, Vingerhoets, Ruben, Brienza, Claudio, Luo, Hongzhen, Bruun, Sander, Meers, Erik, Ravi, Rahul, Beyers, Miriam, Vingerhoets, Ruben, Brienza, Claudio, Luo, Hongzhen, Bruun, Sander, and Meers, Erik

Abstract

To mitigate the risk of eutrophication and minimize adverse environmental impacts, surplus manure in nitrate-vulnerable zones is frequently divided into a liquid and solid fraction. Managing the liquid fraction (LF) typically presents a greater challenge due to its substantial volume. This study aimed to assess the environmental impacts by region and trade-offs of managing surplus LF with inventory data from pilot facilities using a life cycle assessment (LCA). The LF-treatment technologies assessed were (i) nitrification-denitrification (NDN) with field application of effluent (ii) NDN with ammonia stripping and nitric acid scrubbing as a pre-treatment step followed by polishing in constructed wetlands, and (iii) nutrient up-concentration using vacuum evaporation and/or membrane filtration. The LCA results suggested that 60 to 80 % of the environmental impacts occurred locally. Nutrient up-concentration from LF via membrane filtration (reverse osmosis) and vacuum evaporation indicated a better environmental performance, albeit with high uncertainty when compared to the other scenarios. Although ammonia stripping-scrubbing showed environmental benefits, these were offset by high environmental burdens from fugitive N2O emissions and energy demand during NDN. Furthermore, the study identified that managing the effluent after NDN, a source of potassium (K), requires a nuanced approach from policymakers. Firstly, when K fertilization requirements are not met, direct land application of the effluent as a fertigation source can be a viable option. This minimizes the need for synthetic K fertilizer production and its ensuing freshwater ecotoxicity impacts. However, tertiary treatment of NDN effluent via constructed wetlands can be considered to prevent deterioration of soil from the influx of K. Policymakers are encouraged to engage with local stakeholders to tailor solutions based on these trade-offs. Furthermore, future research should focus on the implications of K

Published
2023

43. A facile and efficient synthesis approach of salidroside esters by whole-cell biocatalysts in organic solvents

Author

Yang, Rongling, Wang, Yu, Zhao, Xiangjie, Tong, Zheng, Zhu, Qianlin, He, Xiaoxi, Wang, Zhaoyu, Luo, Hongzhen, and Fang, Fang

Subjects
Histology, Biomedical Engineering, Bioengineering, Biotechnology
Abstract

Salidroside, the main bioactive compound isolated from the plant source of Rhodiola rosea L, possesses broad-spectrum pharmacological activities, but suffers from the low cell membranes permeability and alimentary absorption due to its high polarity. Therefore, a whole-cell catalytic strategy for the synthesis of salidroside esters was explored to improve its lipophilicity. The results showed that Aspergillus oryzae demonstrated the highest biocatalytic activity among the microbial strains tested. For the synthesis of salidroside caprylate, the optimum conditions of reaction medium, Aspergillus oryzae amount, molar ratio of vinyl caprylate to salidroside and reaction temperature were acetone, 30 mg/ml, 10°C and 40°C, respectively. Under these conditions, the initial reaction rate was 15.36 mM/h, and substrate conversion and regioselectivity all reached 99%. Moreover, the results indicated that although various 6′-monoesters derivatives of salidroside were exclusively obtained with excellent conversions (96%–99%), the reaction rate varied greatly with different chain-length acyl donors. This study details an efficient and cost-effective biocatalytic approach for the synthesis of salidroside esters by using Aspergillus oryzae as a catalyst for the first time. Considering the whole cell catalytic efficiency and operational stability, this strategy may provide a new opportunity to develop green industrial processes production for ester derivatives of salidroside and its analogues.

Published
2022

49. Additional file 1 of Toxicity and inhibition mechanism of gallic acid on physiology and fermentation performance of Escherichia coli

Author

Liu, Lina, Ma, Xiaolong, Bilal, Muhammad, Wei, Linlin, Tang, Shijie, Luo, Hongzhen, Zhao, Yuping, Wang, Zhaoyu, and Duan, Xuguo

Abstract

Additional file 1: Fig. S1. Effects of gallic acid on the cell membrane and intracellular components of E. coli. Fig. S2. Pearson correlation between samples. Control-1, Control-2, and Control-3 were three samples of E. coli W3110 fermentation without gallic acid stress; Gallic acid-1, Gallic acid-2, and Gallic acid-3 were three samples under gallic acid stress. Table S1. Differential gene expression genes (up-regulated) of E. coli W3110 under gallic acid stress versus fermentation without stress. Table S2. Differential gene expression genes (down-regulated) of E. coli W3110 under gallic acid stress versus fermentation without stress. Table S3. Gene Ontology analysis of DEGs.

Published
2022
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